Business Glossary

guidelines and principles associated with the workings of a network. Rules surround data and electrical signals on the network, the manner of information transmissions, the way in which the network is accessed, and the processing of applications on the network.

the last part of a web or e-mail address, such as .com, .uk, or the like.

Top-level domains are administered by registrars ultimately licensed by ICANN (see ICANN). Some TLDs are administered by only one registrar, and some, such as .com, are shared by many.

There are three basic types of TLDs. First, the original set, dating from the early days of the Internet:

These are used mostly in the United States, although, except for .mil, they can be assigned anywhere. Other early TLDs, such as .uucp and .bitnet, stood for connections to other networks, and are no longer used.

At the end of the 1990s, several registrars began using .com, .net, and .org indiscriminately for all types of sites. In 2000, ICANN authorized an additional set of international TLDs, as follows:

Mean while, an official set of country code TLDs (ccTLDs) was adopted and maintained. For a complete listing of the ccTLDs, see the tables on pages 585 to 587. Note that the code for the United States, .us, is seldom used.

Most of these ccTLDs are used only in the country to which they belong, but some, such as .tv and .ws, have been resold for use elsewhere - a source of income for small countries, and confusion for everyone else.

a URL for a document in the same directory as the current document. For example, if a web page contains the link <a href="doc1.html"> it will look for the document doc1.html in the same directory as the page containing the link. If you copy both of these files to a different directory or different machine, the link will still work. Contrast absolute URL.

a set of codes that can be inserted into text files to indicate special typefaces, inserted images, and links to other hypertext documents.

The main use ofHTMLis to publish information on the Internet (see World Wide Web). Here is a simple example of an HTML document.

Figure 132 shows how this looks when displayed by a web browser. HTMLfeatures are indicated by special codes, called tags. If there were an HTML tag called XXX, then the characters <XXX> would mark the beginning of this feature, and </XXX> would mark the end. For example, the keywords <TITLE> and </TITLE> mark the beginning and end of the title. <P> marks a paragraph break, and <IMG SRC=filename>embeds an image in the document; many image formats are supported but GIF is the most popular. Codes for special typefaces include the following:

The tag <BR> inserts a line break; note that the line breaks on the displayed web page will not necessarily match the line breaks on the original HTML text. The tag <HR> inserts a horizontal rule.

An unnumbered list of items can be inserted as follows:

An ordered (numbered) list is created in the same manner, except with <OL> used in place of <UL>.

A link to another document looks like this:
<A HREF="XXXX.HTML"> Click here.</A>
That means "Jump to file XXXX.HTML (another HTML document) if the user clicks on the words 'Click here.'" A URL can appear in place of the filename. A link to another place in the same document looks like this:
<A HREF="#XXXX">
This is the text that will display the link</A>
When the user clicks on this link, the browser will jump to the location in the current document marked with
<A NAME="XXXX"> This is the target of the link</A>
Comments (to be ignored by the HTML system) look like this:
<! This is a comment>

Even with no special codes in it, a text file is still a valid HTML document.

Although you can use almost any word processor or page layout program to produce HTML, it is much easier to use a program specially designed for the job (Adobe PageMill, Corel Xara, Microsoft FrontPage, and other "web publishers"). Many of the newer programs provide a WYSIWYG environment for designing web pages and then automatically produce the correct HTML codes.

For other examples of HTML, see dynamic HTML; form; frame; Java; JavaScript; redirect; table.

a computer software application used to view and navigate the World Wide Web and other internet resources.

system of linked smaller computer networks, international in scope, that facilitates data communication such as file transfer, electronic mail, and newsgroups between different entities.

a URL that contains the full address, identifying the machine, directory, and file. For example, if a web page contains the link:
<a href="http://www.tcoll.edu/ ~ kstanwell/doc1.html">
it will find doc1 in the public directory of user kstanwell at the computer labeled www.tcoll.edu. Contrast relative URL.

the character ˜. Under UNIX and in many web addresses, the tilde indicates the home directory of a particular user; for example, ˜smith is the home directory of the user named smith.

a protocol for using one computer as a terminal on another; only textual communication is supported, not graphics.Telnet is widely used to access UNIX systems remotely. To use it, type telnet or tn at a command prompt, or type a URL such as telnet:abc.xyz.com into your browser.

a hypertext protocol that was used in the early 1990s, before HTTP. The name "gopher" is a pun on "go for" (i.e., go and get things).

a standard method of publishing information as hypertext in HTML format on the Internet. URLs (addresses) for web sites usually begin with http:.

Internet system for worldwide hypertext linking of multimedia documents, making the relationship of information that is common between documents easily accessible and completely independent of physical location.