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CLICK HERE TO VISIT THE WORLD 1000!

 

 

Terms/Definitions/Info

This page is provided to help explain some of the terms and that you may encounter as you explore the World Wide Web (WWW).   Additionally, other computer related, useful information will be added to this page as requested. To request additional information on a specific topic, contact the webmaster.

Terms and Definitions

Internet Terms                                              Net Dictionary

BBS

A bulletin board system lets you post messages—and sometimes program and text files—for other members to see. Many BBSes also give you an email account and access to the Internet. There are tens of thousands of BBSes; most are operated by special-interest groups, while others are maintained by schools, research institutions and government agencies.

E-mail

Electronic mail is a message that s passed between people over a computer network. An email message looks a bit like a business memo—it has a header that lists the sender s name, the date and time sent, and the subject.

FAQ

Pronounced fak, this term is short for "frequently asked questions. The first time you go to a BBS or a Web site, it s a good idea to read the FAQ file if there is one before posting new questions— they may already have been asked and answered.

Home page

Think of this as a Web site s title page—it typically describes the individual or institution operating the site. In most cases, home pages include hypertext links to other areas of the site and often to related information at other Web sites.

Hypertext

This term refers to text that s cross-referenced—linked—to related information on the Web. Links operate like the "See also" section in an encyclopedia article. Clicking on links, which are displayed in a different color or typeface, takes you to the related material automatically.

IRC

Internet Relay Chat, like the telephone party lines of yesteryear, allows people anywhere on the Net to join in real-time discussions by typing messages on their keyboards and reading replies on their screens. IRC is split into channels, like those on a CB radio; each has a different conversation.

Netiquette

Even the Net has loose "rules"—or at least conventions of politeness recognized by regular users. For instance, it violates Netiquette to type a message all in capital letters—it s like SHOUTING—or to promote a commercial enterprise in a general-interest newsgroup or BBS.

Newsgroups

Usenet, a bulletin-board system on the Internet, houses more than 20,000 single-topic message boards called news-groups. They can be unmoderated—meaning anyone can post a message—or moderated—submissions are directed to a moderator who edits or filters them before posting the results.

URL

Pronounced either "earl" like a man s name or U-R-L, a Uniform Resource Locator is an address—such as www.whitehouse.gov—that identifies a site on the Internet. The suffix .com denotes a commercial site, .edu a site based at an educational institution, gay a site run by a governmental organization and so on.


Other Information

  What is meant by a 3GL with regard to computers?

GL's are generational languages!

A 1st GL is one which directly manipulates the computer hardware through the hard—wiring of boards and such. This was how the first programs were done on computers years and years ago. If you ever see old footage of those big computers and all those wires plugged in here and there, that s the program. This also includes code written in machine language (which no one does). An EXE tends to be in machine-language, but this is because a program written in a later generation language is compiled to the native tongue, so to speak.

A 2nd CL is one which is structured and has a syntax (like any language, all programming languages have a syntax that defines how to use it, just like English or French does). But it is low-level code, where the programmer controls many of the program s variables and registers (hardware storage areas on a CPU). This code is considered extremely efficient, because you tell the program exactly how and when to do things. Asembly language falls under this category. It is very hard to read and debug. It also is usually tied to a specific processor. Since how the under-pinnings of a computer differ between types and Operating Systems, a program in Assembler written on a PC would not work on any other platform (Mac, Unix box, etc.)

A 3rd GL is a structured language, but there is an abstraction layer between the program and the hardware, and the compiler (which compiles source code into applications) handles all concerns and worries regarding the processor, registers, etc. This is called abstraction (or an abstraction layer) . Most of your major languages (like C, Pascal, COBOL even) fall into this category. The main thing is that since the program has no regard to the hardware, the code itself can be used on multiple platforms (assuming there is a compiler written for that platform which can compile the code) . So, a standard C program written for a PC could work on a Mac with just a recompile. Unfortunately, 3rd GLs are pretty simplistic in the provided functionality (to make the language standardized, for example, there is no specification for any type of windowing features), so all compiler manufactures add in there own extensions to the language to make programming easier on whatever platform. But this cuts down on the cross—platformness of the language (unless the compiler maker creates a compiler with those extensions on other platforms as well)

While a 3rd GL abstracts you from hardware, it does nothing to abstract the program from how data is stored and used in your program. In all 3GLs, the programmer knows the internal structure of data and how it is stored/manipulated by the program (even if the language does the manipulation, the programmer still knows the details)

A 4th GL is one where there is even a greater abstraction layer between the program and the hardware. Visual Basic falls under this category (it also is a little fuzzy on the specific reasons on why it is fourth rather than 3rd, except it sounds better to Microsoft, I m sure). In a 4GL, data is abstracted from the program as well. The programmer defines a variable to hold a string (say the Course Title), but does not know how the string is stored, and cannot directly manipulate the string (you can manipulate the string, but only through the interface defined by the language). This moves the burden of handling the data away from the programmer and onto the compiler, making the programmer s job easier and the code clearer. It also allows the compiler to tweak or change the way data is stored internally, without it affecting the program itself.