Understanding the Internet: Key Terms and Concepts

Posted on Jan 17, 2025 in Contemporary Music Composition

Unit 5: The Internet – Key Definitions

These are the definitions and concepts of Unit 5, Item 4 of the book, pp. 94, 95. Each definition is written as simply and briefly as possible, followed by some clarifications for better understanding. I hope this helps you.

Internet

A worldwide network of computers that emerged from the interconnection of thousands of local networks worldwide through routers and gateways. The various interconnected networks are highly heterogeneous, i.e., different in nature, technology, size, and other characteristics. This is possible through the use of TCP/IP.

TCP/IP

The communications protocol used on the Internet, allowing computers on different networks to exchange any kind of information. TCP/IP is the only thing that both computers must share to communicate over the Internet. It provides reliable service and easy end-to-end connection.

WWW – World Wide Web

An Internet service that provides access to hypertext documents (web pages) located anywhere in the world. It uses TCP/IP. The Internet is a communications infrastructure, while the WWW is a service that uses this infrastructure. Other services that use the Internet infrastructure and TCP/IP are:

  • FTP – File Transfer Protocol, a service that allows people to exchange files.
  • Email – Email service that uses POP3 and SMTP. Most currently used webmail is based on the WWW.
  • Telnet – Remote Terminal Services lets you control a remote computer.

URL – Uniform Resource Locator

The full address (including the protocol) of a resource on the Internet, whether a web page or another file type. A URL is a string that uniquely identifies an Internet resource:

  • http://: protocol to be used for obtaining the resource
  • hazel: name of the computer (web server) where the resource is located
  • .usal.es: domain(s) and subdomain (USAL) complete the computer name
  • /files/: path within the computer file system
  • ejercicios.pdf: name of the resource itself

Alternatively:

http://83.124.90.21/archivos/ejercicios.pdf

where 83.124.90.21 is the public IP address of a web server.

Note that many web servers are called www, i.e., for example: www is the name of a server (computer) and not a protocol.

Web Server

A computer connected to the Internet that has a server program installed. It provides web pages to other computers when requested. A web server knows the HTTP protocol and uses it to provide web pages to clients. Web clients (web browsers) connect to it to request a page, also following the HTTP protocol.

HTTP – Hypertext Transfer Protocol

The Internet protocol used to exchange web pages and sometimes other file types such as PDF.

Hypertext

A file or web page written in HTML that, in addition to normal text, includes tables, images, animations, and hyperlinks. It fundamentally contains links or references to other websites and files. Unlike traditional text (a book) in which we read the different pages in sequential order, hypertext pages can be read without following a prescribed order, jumping from one to another at any time, relating the information in a more complex way.

Hyperlink

Also called a link, it is a reference to another website or file (PDF, image, sound, etc.) contained in a web page. To access the referred resource, simply click on the hyperlink, which normally appears as underlined text, but can also be an icon, phrase, or any other element.

HTML – Hypertext Markup Language

The language used to write or create web pages. When we order a website through the browser, what it receives from the web server is a plain text file like this:

DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"

Our browser translates the appearance of text, images, and colors as we see them on the screen. You can see the true aspect of a website in the browser’s “View” menu.