 | www.brauer-online.net | ||
| • | S e t t i n g s | – recommended for your web browser and this web site | |
| • | Web Browsers | – suitable to display this web site without problems | |
| • | Technologies | – employed to design this web site | |
| • | G l o s s a r y | ≡ footnotes … | |
First, some brief introductory remarks about the Internet, the World Wide Web, and web browsers which are intended for Internet users who do not deal with these subjects professionally, or to whom above mentioned three topics do not mean anything. …
For more than a decade the continuously growing worldwide electronic exchange of data and information has been made possible by the Internet's 1 different and task orientated Internet services. Most likely, electronic mail (e-mail), electronic file transfer(FTP) and the World Wide Web (WWW) are the best-known Internet services because they are fairly frequently used.
What is common to all these services is that some computers function as service providers or servers and others as service clients. That is why there are e-mail servers, FTP servers and Web servers on the one hand, and on the other hand significantly more e-mail clients, FTP clients and web clients part of the worldwide computer network, the Internet. Whether a computer acts as server or client is not determined by its hardware components but the respective server or client software installed
The probably fastest and exponentially growing Internet service is the World Wide Web, or just WWW or web 2, which is frequently but mistakenly equated for the Internet. The Internet is the worldwide computer network that naturally, i.e. “internet-like”, serves as worldwide communication basis for the WWW Internet service.
On web servers, which may be institutional or commercial mainframe computers as well as small home computers and that are spread out all over the world, more or less relevant information on all conceivable subjects is stored. Thanks to appropriate software web servers are capable of publishing their stored information as web pages(s) on the Web or the Internet, so all or just certain web clients may access, open, and retrieve the information worldwide.
Web clients do not only need a mandatory Internet access to be able to access web pages 3, web sites 4 or home pages 5 but also a web client software that cannot only open web documents but also display their contents, so they can be read by visiting web clients. …
A web browser 6 is nothing but a web client software, which quite obviously already enabled you to access this web site or rather this web page. It not only (automatically) downloaded this web page from a web server but has also enabled you to currently read it. (Thanks for your being interested!)
There is not the one and only web browser but a whole host of web browsers. The fact that they, despite all absolutely necessary common grounds, interpret and display web pages quite differently has actually been the reason for publishing this web page. After all, every effort shall be made to ensure that this web site is displayed as intended by its author.
A web page 3 may be addressed and retrieved through its so-called URI 7 or URL 7 by a web browser connected to the Internet.
If “only” a web site 4 is selected, the addressed web server will automatically return the respective home page 5 to the web browser.
Whenever a web page is retrieved its mandatory HTML code 8and some other optional program code (tab.3) is automatically downloaded to the computer of the respective web client. That is where at about the same time program code is interpreted 9 by integrated (interpreter) software, which may cause a web page to be displayed gradually on a web client's monitor screen due to its large size or slow data transmission.
• The program code of a web page is usually not only based on the mandatory markup language HTML.
More often than not, in part quite different, standard and non-standard program technologies and programming languages are employed in addition to HTML and contribute to the complete appearance of a web page.
• The developer or author of a web site decides which program technologies and/or programming languages in addition to HTLM he would like to use for designing his web page. The optional web technologies used to design this web site to date are listed in table 3.
• It is up to the visitor of a web site to decide completely irrespective of the web site author if and if need be how optional web technologies, provided by a web server, are to be executed on his computer. More or less sophisticated settings of his web browser enable the visitor of a web site to determine type and extent of usage of local web technology.
S e t t i n g s – recommended for your web browser and this web site
It is the visitor of a web site who solely controls the following, below listed settings termed "recommended". Rightly so it is left up to only him to decide on what settings to use how, i.e. which of the implied web technologies or options he may want to use or not.
Table 1 lists the settings you will be asked to activate and which will enhance design, contents and technical features of this web site. Your activating these settings will not have any disadvantageous consequences except for maybe slightly increased download times for web pages.
Unfortunately, web browsers will sometimes be configured quite differently. Usually somewhere on a web browser menu there is a menu item called settings, Internet options or something similar, from where different optional settings can be accessed that again may vary from browser to browser. Not all web browsers offer the same optional settings, and options of the individual settings reveal different levels of sophistication.
Before checking and changing any of the following settings make first of all sure you are familiar with all the optional settings of your web browser. It may well be that program code will be interpreted without problems and accurately although your web browser does not have all the optional settings listed below. …
The web browsers listed in table 2 are all “suitable to display this web site without problems”.
| Table 1. recommended web browser settings for www.brauer-online.net | ||||||||||||||||||||||||||||||||||||||||||
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Web Browsers – suitable to display this web site without problems
First of all, for web browsers goes the same that goes for operating systems, word processing programs and other software programs: “There are many excellent products from many equally excellent product developers”.
Every user prefers “his” product because he very much appreciates its strengths and skills and has learned to live with its weaknesses. …
And so your currently preferred operating system and preferred web browser have been identified as follows.
| Details about your current operating system and web browser : | ||||||||||||||||||||||||||||
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As already mentioned earlier, a web page's or site's complete display is not only based on the mandatory markup language HTML but also more often than not on HTML complementing, standardized and non-standardized programming technologies and languages.
Some of these web technologies were already briefly explained (tab.1) earlier only as far as needed to possibly adjust settings.
As web site visitor you usually do not need to understand the underlying technologies. You should only know that there are many different web browser versions, sometimes referred to as “generations” because they are based on each other chronologically, that may differ technologically quite significantly.
The fact that web browsers of different providers differ significantly may, for a moment, be taken as a matter of course to be expected. After all, word processing programs of different software producers differ just as much as models of different automobil manufacturers do. …
Worldwide communication over the “the net of nets” or the Internet depends per se on basically cross-platform, globally understandable and universal web technologies.
That is why in the summer of 1995 the World Wide Web Consortium 
, abbreviated as W3C was founded. It works out or administers standards for different but unfortunately still not all web technologies. So there are already, amongst others, several generations of standards for the hypertext markup language 8 HTML and cascading style sheets (4) CSS, to just name the most important ones. You will find a list of the technologies, versions und standards used for designing this web site in table 3 of the following section.
Theoretically, all web browsers adhering to W3C or other standards should, irrespective of software producers, interpret HTML and CSS coded web pages exactly the same and display them also exactly alike on a web site visitor's screen.
Practically though, different web browsers and browser versions do not necessarily interpret one and the same web page code exactly the same. This is partly due to different and/or not (yet) completely integrated standards or differing web browser interpreter software. …
Maybe the explanations just given do convey why it is just not “that easy” to develop a web site that fits the requirements and peculiarities of every web browser.
This web site has been developed for and tested with web browsers of “more recent generations”. The following table lists web browsers and versions, which retrieve and display this web site without problems.
| Table 2. Web browsers, suitable to display www.brauer-online.net without problems | ||||||||||||||||||||||||||||||||||||||||||
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Maybe, you can do me a little favor:
Should you use an operating system, a web browser or a browser version combined in a way that is not listed in table 2, please, be so kind and keep me simply informed per e-mail hp@brauer-online.net as follows:
1. Copy (see below) the “details about your current operating system and web browser” to an e-mail message.
2. Please, let me know, if you could retrieve and download this web site without any errors.
Your details about the operating system and web browser will be added to the above list.
3. However, should an error have occurred, please, describe it as detailed as possible.
• Your personal data will be handled confidentially except for the “details about your current operating system and web browser”.
• Instructions on how to copy web page contents
1. Mark the “details about your current operating system and web browser”.
(Move over text while holding down left mouse button
and watch how text and background color change.)
2. Quickly click right mouse button to see context sensitive menu.
3. Choose copy from the menu so marked text will be copied to the so-called clipboard.
4. When you subsequently move to your e-mail program (e-mail client) and choose paste from its menu
you will be able to paste text from the clipboard into currently edited e-mail message.
Technologies – employed to design this web site
As already emphasized in previous sections, there are several web technologies used to design a web site. Governed by specific requirements and/or demands, a given developmental environment, personal skills and not least personal taste a web site developer uses different web technologies to very different degrees.
The following table lists all the web technologies employed to design this web site and is meant to establish transparency for all interested web site visitors. Meaning and function of itemized technologies cannot be explained here, though.
Even without programming related understanding and under certain circumstances may some of the brief comments in table 3 help explain or avoid incompatibilities between this web site and your current web browser. Pay particular attention to the different versions mentioned.
Notice: In case of any anticipated incompatibilities always check the settings (tab.1) of your web browser first and adjust respective settings if needed. Thereafter and based on comments in table 3 you may try to uncover possible reasons for incompatibilities.
| Tabelle 3. Web technologies employed to design www.brauer-online.net | ||||||||||||||||||||||||||||||||
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Known, but in this table not listed web technologies have indeed not been used to date!
| 1. | Internet: the “network of networks”, which links a “very large” number of (local and regional) networks or computers to only one worldwide accessible computer network. Access to the Internet via modem, public phone line or satellite and a so-called Internet Service Provider (ISP) is handled by the Point-to-Point Protocol (PPP), which has become an industry standard. Communication over the Internet, i.e. data transfer and addressing users (computers), is based on the standardized Transmission Control Protocol / Internet Protocol (TCP/IP). | ||||||||||||||||||||||||||||||||||||||||||||||||||||
| 2. | Web: frequently used short term for World Wide Web, the worldwide accessible Internet information service, which provides information by means of web documents labeled with so-called hyperlinks. The (hyper)links enable the worldwide networking of information (documents), which has not only contributed to the naming of the Web but also to its great popularity. | ||||||||||||||||||||||||||||||||||||||||||||||||||||
| 3. | Web page: is the generally used term for a web document, which formally resembles a single book page. (The terms web page, web site, and home page are occasionally confused or improperly used.) The reader of a book may open single pages by their page numbers and read them. Likewise a web visitor may, with the help of a web browser, retrieve web pages by their Uniform Resource Locator, better known as URL, and subsequently read them. Web pages or documents are sometimes called HTML documents because they are created with the markup language HTML. | ||||||||||||||||||||||||||||||||||||||||||||||||||||
| 4. | Web site: describes all the web pages and supporting files put together on a web server by a provider like for instance a company, an organization or a private individual, to be published on the web. Just as a book or catalog can contain many pages, the web site of a business company may host quite a few web pages, too. (The terms web site and web page are occasionally confused.) A domain name or domain name address like for example brauer-online.net serves as name for a web site. It is the essential part of a web server address that indeed tells the “site” on the worldwide network where the web pages of respective web site are located. | ||||||||||||||||||||||||||||||||||||||||||||||||||||
| 5. | Home page: refers to the “start page” of a web site and is very similar to a book's table of contents. Every web site hosts a home page that is usually called default.html, index.html, home.html or welcome.html. When calling only a web site without any of its web pages, like for instance http://www.brauer-online.net/ , a file named default.html, index.html etc. is searched for and retrieved because of respective web server settings. Calling a web site without its home page is common practice and should only be deviated from if a home page's proper name is known for sure. (By the way, the home page of www.brauer-online.net is named index.html , so the web site may be called correctly with http://www.brauer-online.net/index.html .) Occasionally, someone is said to have his or her “own home page”. Such statement certainly does not really refer to someone's home page, (e.g. index.html ) but very likely to someone's web site (e.g. www.brauer-online.net ). | ||||||||||||||||||||||||||||||||||||||||||||||||||||
| 6. | Web browser: describes software (syn.: application or computer program) a client of the World Wide Web Internet service needs to browse the web, i.e. to look at web pages. Communication between web client (syn. HTTP client ) and web server (syn. HTTP server ) is handled by the Hypertext Transfer Protocol (HTTP), which has been standardized by the World Wide Web Consortium . From a technical point of view this Internet service protocol is subordinate to the TCP/IP, which is in charge of the underlying Internet communication. | ||||||||||||||||||||||||||||||||||||||||||||||||||||
| 7. | URI or URL: address naming format for resources (data files) on the Internet standardized by the Internet Engineering Task Force  (IETF).URI or Uniform Resource Identifier is the generic term for URN or Uniform Resource Name and URL or Uniform Resource Locator. The URN is unimportant for the web. Because URI and URL are practically identical, they are, not quite correctly, used synonymously. A URI consists of several components: Internet service protocol :// server address : port / path / file name . file type Internet service protocol and server address are requisite URI statements. • Internet service protocol :
name of the service protocol to be used followed by a colon. Web browsers require the name http (see above) to be able to download web documents from a web site or ftp to download files from a FTP-Site. • Server address :
network address of server (syn. host computer, host), i.e. of the computer on the worldwide network (Internet) where in general data are located. The string with a maximum length of 255 characters may contain theoretically up to 127 (sub)domains (see below) that each may not have more than 63 characters. ♦ IP addresses :
All computers participating in the (current) data traffic over the Internet are identified by unique so-called static or dynamic IP addresses. An IP address is a 32 bit number put down in a special format referred to as dotted-quad notation. Four 8-bit numbers (octets) separated by dots enable over 4 billion different 32-Bit IP addresses ranging from (decimal) 000.000.000.000 to 255.255.255.255. IP addresses are important for and used by the TCP/ IP, and may be compared to phone numbers. Just like a phone number is made up of an area code and a local code (residential phone number), an IP address is made up of a network number and a host (computer) number. Depending on the size of their network parts (1 to 3 octets) Class A, B and C IP addresses are defined. There are for instance about 2 billion class C networks or network numbers with 254 users each. The fourth octet .000 and .255 is reserved for special tasks. … ♦ Domain Name System :
At the beginning of the 1980s the multitude of difficult to remember and meaningless IP addresses afflicted with errors led to the development of the Domain Name System or DNS, which serves the translation of IP into name addresses and vice versa. The Internet Corporation for Assigned Names and Numbers or ICANN is responsible for its organization and administration.The DNS is a server or host computer addressing system with a hierarchical structure similar to the mailing address format. An address like addressee ← street ← city ← federal state ← country (← world) reveals a geographically defined hierarchy. The example displays address levels separated by direction arrows (←) with from right to left decreasing hierarchy. The worldwide available and computer assisted DNS uses domain levels separated by dots, which also reveal from right to left decreasing hierarchy. The term (Internet) domain stands for a more or less uniquely defined partial area of the Internet network.
Based on the DNS format, addressing a server starts with 2 slashes (//) and ends with one slash (/) that is frequently omitted if only a web site and no web document or page is to be called. (It is recommended though, not to omit the ending slash because an automatic but futile document search will be avoided by an unambiguous notation.) When a web browser submits an address to the Internet it is read by the appropriate DNS or name servers (see below) from right to left in accordance with its hierarchical structure. The period left of the ending slash, called dot nothing, is practically never indicated. It stands for the highest level or domain of the Internet, the root domain, i. e. the entire Internet all other levels are subordinate to. ♦ Top-Level Domain :
The top-level domains or TLDs are often just called domains as within the Internet hierarchy they each represent the highest level of their respective subordinate levels. Altogether only about 200 TLDs (Internet sections) are defined exclusively by the ICANN (see above). There are country specific (country code) ccTLDs like at (Austria), de, ch, fr, it, uk, us and not country related, generic gTLDs like com (commercial), org, net and others. Each TLD is administered by an international or national organization, which has been authorized and accredited to do so by the ICANN. The ccTLD de for instance is administered by the Deutschen Network Information Center (DE-NIC). Every Internet user who wants to carry the TLD de in his address, must have himself, that is his computer, be registered with the DE-NIC to obtain a unique second level domain or SLD (see above). Most of the time so-called Internet Service Providers (ISP) carry out these registrations for their clients, because they have a certain contingent of IP classes or respective IP addresses at their disposal. ♦ Domain name and registration :
The worldwide similarly practiced mandatory registration of a domain name (= SLD.TLD) with the responsible accredited TLD organization guarantees its uniqueness in the worldwide Internet, as checking the domain name's uniqueness is part of the registration process. The different meaning of domain (= TLD) and domain name/address (= SLD.TLD) should be pointed out as occasionally both terms are used synonymously by mistake. The second important element of the registration process is the translation of the unique domain name SLD.TLD) into an equally unique IP address (www.xxx.yyy.zzz) of the allotted contingent (see above) as the relevant TCP/IP does not need a domain name but a 32-bit IP address. Domain names are often called domain addresses because they correspond to IP addresses. All the information on addresses, i.e. domain name and corresponding IP address are stored in DNS databases (see below). The address details left of the SLD, i.e. below the domain address level, beginning with the 2nd sub domain or third level domain (see below) do not require the registration by an organization accredited by the ICANN, because they are within the responsibility of so-called local network administrators (see below). The entry of domain names and corresponding IP addresses into DNS databases associated with the registration is the basis for more sophisticated addressing techniques that go beyond the simple 1:1 translation of one domain name into one IP or server address respectively. 1. Domain name aliases :
When registering, one unique IP address may be affiliated with aliases or alias names provided uniqueness is considered. In the DNS database the domain names: wwww.brauer-online.net and brauer-online.net stand for or represent the IP address 212.227.119.98 . Due to their respective DNS database entries both domain names lead to the identical server address. 2. Name based virtual hosting :
Available only since the mid 1990s this web site hosting technique has been increasingly employed facing an ever-growing demand for IP addresses. In the beginning of the Internet one web site corresponded to one domain name, which again corresponded to one IP address or one server address. With name-based virtual hosting several thousand web sites or domain names may share a single IP address and thereby one server, so the limited supply of available IP addresses can be dealt with “more carefully”. As with the awarding of alias names maybe several thousand unique domain names are assigned to one single IP address in a DNS database. In case of name-based virtual hosting a domain name does not stand (any more) for a web server or its IP address but rather for a particular, limited web space or section on a web server. When calling a domain address like http://brauer-online.net/ the connection is established in to two steps. In a first step the connection to the server is established via the corresponding IP address 212.227.119.98 . Only then in a second step the server itself establishes the connection to the web site with the help of its domain name brauer-online . Provided a 1:1 corresponding domain name and IP or server address, or an alias domain name for one server address is entered in a DNS database, the connection to the domain address may be established by directly calling its IP address, e.g. http://123.456.78.9/ . However, if a domain address is based on “name-based virtual hosting” calling its IP address directly will establish a connection with the specified server (host computer). The second important step, that is establishing a connection with the supposedly addressed domain address like a web site will fail because the web site name has not been given. Instead a mostly meaningless default web page of the web server will be retuned to the web browser. ♦ Sub domains :
The sub domain name located farthest on the left or directly to the right of the 2 slashes (//) denotes the name of the server. In the server address //www.brauer-online.net./ “www” is the server's name. The server can be named arbitrarily by the responsible local network administrator and could for instance be called “jack” or “k56ab”. The name “www” is very frequently used just because it is first of all easily remembered and secondly it signals the computer's task, which is the publication of data on the World Wide Web. The complete server address especially of larger companies, organizations or institutions more often contains several sub domains or domain levels below the actual, registered domain address. … Example: //p-abc.cardiology.medicine.medical-school.university-of-xyz.us./ . The registered domain name is: “university-of-xyz.us”. Below the domain address there is, likely along with others, the university-owned local network “medical-school”, which administers the subordinate network “medicine” of the respective department. This network again administers the network “cardiology”, which hosts and administers the computer named “p-abc”. The administrator of the network “cardiology” has to assign a local IP address to the computer “p-abc” and enter respective address information into the local DNS database before the computer “p-abc” can participate in Internet data traffic. Data traffic on local networks is also based on translations of locally unique sub domain names into locally equally unique IP addresses. This example illustrates the typical, hierarchical administrative structure within the sub domain list of a complete and a bit longer server address. Each sub domain administers its directly subordinate sub domain and is itself administered by its directly superodinate sub domain. This way third level domains, for instance, are usually administered by the directly superordinate Internet service provider (ISP) that stores respective address information in its ISP DNS databases. This example also illustrates how he Internet domain address connects the global Internet network with an extensive local network. Sub domains are also frequently used to lead a web site visitor directly to a subordinate web site directory. ♦ Domain name databases and server : Domain name servers or name servers or DNS servers, for short, are computers spread out all over the worldwide network, which host DNS databases with address information (domain names, IP addresses and additional domain administrative data) of servers, and are able to „handle” respective address requests. All name servers have in common that thanks to their administered DNS databases they are able to resolve sub domain names, i.e. to translate them into IP addresses. Root name servers, TLD name servers, SLD name servers, domain name servers, ISP name servers and DNS servers of local networks may be distinguished. The hierarchy of the domain name system also determines the corresponding hierarchical communication of the networked name servers. Each DNS server communicates only with DNS servers of the directly superordinate as well as directly subordinate hierarchical level. Root name servers administer DNS databases with all TLDs and may pass on an address request to the appropriate TLD name server. The TLD name server administers a DNS database with its subordinate SLDs, so that it in turn may pass on the request to the appropriate SLD name server. … This way a complete server address eventually is resolved and each individual Internet computer may be accessed by its IP address. There are web sites like infobear.com , eamnesia.com or canufly.net with service web pages, which offer to retrieve (free of charge) stored information on domain names and IP addresses from top-level domain databases.• Port :
so-called TCP port number (between 1 and 65535) located left of the server address, separated by a colon and followed by a slash (/). Usually it does not need to be given, as it is automatically and correctly set by the server. • Path :
if need be name of (nested) server directory where resource is located followed by a slash (/). • File name :
name of resource or data source. Web browsers expect the name of a web page followed by a period. • File type :
name of type of resource or data source. Web pages usually require the file type extension html or htm. | ||||||||||||||||||||||||||||||||||||||||||||||||||||
| 8. | HTML: stands for Hypertext Markup Language, a (text) markup language standardized by the World Wide Web Consortium (A markup language like HTML contains for instance instructions to mark up text to be displayed in italic or bold typeface.) HTML forms the mandatory program controlled fundamental basis of the World Wide Web Internet information service. It serves to mark up text documents and to structure them, i.e. divide them into any context determined informational units, which if need be may be referenced. The markup language HTML can very easily retrieve especially “text objects ” from inside a document as well as from the whole worldwide Internet with the help of hyperlinks. Therefore, and with the availability of computer and networking technologies, HTML has grown into the tool for in the true sense of the word universal networking of information. Documents written with HTML are called HTML documents and carry the file type extension html or htm†. As web browsers are used to retrieve and display HTML documents as legible pages they are frequently also called web pages. † Under DOS™ and prior to Windows 95™ file type extensions were limited to a maximum of 3 characters. | ||||||||||||||||||||||||||||||||||||||||||||||||||||
| 9. | to interpret: meaning to translate. Usually a computer program's source code is either compiled or interpreted. In case of interpreting the instructions of the source code are translated one after the other into executable machine language and executed immediately before going on to the next instruction. The (legible) source code is passed on to the so-called interpreter (special software) of a user or respective application software. Programming languages like Basic, HTML and JavaScript belong to the group of interpreter-level languages. In case of compiling the complete source code is translated by a so-called compiler (special software) into binary machine or object code. Only the (illegible) already compiled, executable object code is passed on to a user, where it may be executed. Programming languages like C, C++, Fortran and Java belong to the group of compiler-level languages. | ||||||||||||||||||||||||||||||||||||||||||||||||||||
