
The Internet is a worldwide collection of networks that links millions of businesses, government offices, educational institutions, and individuals. Data is transferred over the Internet using servers, which are computers that manage network resources and provide centralized storage areas, and clients, which are computers that can access the contents of the storage areas. The data travels over communications lines. Each computer or device on a communications line has a numeric address called an IP (Internet protocol) address, the text version of which is called a domain name. Every time you specify a domain name, a DNS (domain name system) server translates the domain name into its associated IP address, so data can route to the correct computer.

You can access the
Internet through an Internet service provider, an online service provider, or a
wireless service provider. An Internet service provider (ISP)
provides temporary Internet connections to individuals and companies. An
online service provider (OSP) also supplies Internet access, in
addition to a variety of special content and services. A wireless service
provider (WSP) provides wireless Internet access to users with
wireless modems or Web-enabled handheld computers or devices.
Employees and students
often connect to the Internet through a business or school network that connects
to a service provider. For home or small business users, dial-up access provides
an easy and inexpensive way to connect to the Internet. With dial-up
access, you use a computer, a modem, and a regular telephone line to dial
into an ISP or OSP. Some home and small business users opt for newer, high-speed
technologies. DSL (digital subscriber line) provides high-speed
connections over a regular copper telephone line. A cable modem provides
high-speed Internet connections through a cable television network.

The most widely used
service on the Internet is the World Wide Web. The World Wide Web
(WWW or Web) consists of a worldwide collection of electronic
documents called Web pages. A browser is a software program used
to access and view Web pages. Each Web page has a unique address, called a
URL (Uniform Resource Locator), that tells a browser where to
locate the Web page. A URL consists of a protocol, domain name, and sometimes
the path to a specific Web page or location on a Web page. Most URLs begin with
http://, which stands for hypertext transfer protocol, the
communications standard that enables pages to transfer on the Web.

A search engine is
a software program you can use to find Web sites, Web pages, and Internet files.
To find a Web page or pages, you enter a relevant word or phrase, called
search text or keywords, in the search engine’s text box. Many
search engines then use a program called a spider to read pages on Web
sites and create a list of pages that contain the keywords. Any Web page that is
listed as the result of the search is called a hit. Each hit is a link
that can be clicked to display the associated Web site or Web page.

There are six basic types
of Web pages. An advocacy Web page contains content that describes a
cause, opinion, or idea. A business/marketing Web page contains content
that promotes or sells products or services. An informational Web page
contains factual information. A news Web page contains newsworthy
material including stories and articles relating to current events, life, money,
sports, and the weather. A portal Web page offers a variety of Internet
services from a single, convenient location. A personal Web page is
maintained by a private individual who normally is not associated with any
organization.

Many exciting Web pages use multimedia. Multimedia refers to any application that integrates text with one of the following elements: graphics, sound, video, virtual reality, or other media elements.
A graphic is a digital representation of information such as a drawing, chart, or photograph. Two common file formats for graphical images on the Web are JPEG (Joint Photographic Experts Group) and GIF (Graphics Interchange Format), which use compression techniques to reduce the size of graphics files and thus speed downloading.
Animation is the appearance of motion created by displaying a series of still images in rapid sequence. One popular type of animation, called an animated GIF, uses computer animation and graphics software to combine several images into a single GIF file.
Audio is music, speech, or any other sound. A common format for audio files on the Web is MP3, a popular technology that compresses audio. More advanced Web audio applications use streaming audio, which transfers audio data in a continuous and even flow, allowing users to listen to the sound as it downloads. Video consists of full-motion images that are played back at various speeds. Video files often are quite large in size. The Moving Pictures Experts Group (MPEG) defines a popular video compression standard. Streaming video allows you to view longer or live video images as they are downloaded.
Virtual reality (VR) is the use of computers to simulate a real or imagined environment that appears as a three-dimensional (3-D) space. A VR world is an entire 3-D site that contains infinite space and depth.

Pull technology is a method of obtaining information that relies on a client such as your computer to request a Web page from a server. On the other hand, Webcasting, also called push technology, is a method of obtaining information in which a server automatically downloads content to your computer at regular intervals or whenever updates are made to the site. Webcasting saves time by delivering information at regular intervals and allows users to view Web content when they are offline, that is, when they are not connected to the Internet.

Electronic
commerce (e-commerce) is a financial business transaction that occurs
over an electronic network such as the Internet. Today, there are three types of
e-commerce. Business to consumer (B-to-B or B2C)
e-commerce consists of the sale of goods to the general public. Customers
visit an online business through an electronic storefront, which contains
descriptions, graphics, and a shopping cart that allows customers to
collect their purchases. Consumer to consumer (C-to-C or
C2C) e-commerce occurs when one consumer sells directly to
another. An online auction is an example of consumer to consumer
e-commerce. Business to business (B-to-B or B2B)
e-commerce, which is the most prevalent type of e-commerce, takes place
between businesses, with businesses typically providing services to other
businesses.

A variety of services are
used widely on the Internet, including e-mail, FTP, newsgroups and message
boards, mailing lists, chat rooms, and instant messaging. E-mail
(electronic mail) is the transmission of messages and files via a
computer network. You use an e-mail program to create, send, receive,
forward, store, print, and delete messages. To receive messages, you need an
e-mail address, which is a combination of a username and a domain name
that identifies a user.
FTP (File Transfer Protocol) is an Internet
standard that allows you to upload and download files with other computers on
the Internet. An FTP server is a computer that allows you to use FTP to
upload files to, and download files from, an FTP site. With anonymous
FTP, anyone can transfer some, if not all, available files. A
newsgroup is an online area in which users conduct written discussions
about a particular subject. The computer that stores and distributes newsgroup
messages is called a news server. You use a program called a
newsreader to access a newsgroup, read previously entered messages
(called articles), and add (post) messages of your own.
A thread
consists of the original article and all subsequent related replies. In a
moderated newsgroup, a moderator reviews articles and posts them,
if appropriate. A message board is a popular Web-based type of discussion
group that does not require a newsreader and typically is easier to use than a
newsgroup. A mailing list is a group of e-mail names and addresses given
a single name. To add your e-mail name and address to a mailing list you
subscribe to it; to remove your name, you unsubscribe.
A chat is
real-time (meaning everyone involved in the chat is online at the same
time) typed conversation that takes place on a computer. A location on an
Internet server that permits users to chat is called a chat room. Some
chat rooms support voice chats and video chats, where you can hear
or see others and they can hear or see you as you chat. A chat client is
a program on your computer that allows you to connect to a chat server and start
a chat session. Instant messaging (IM) is a real-time Internet
communications service that notifies you when one or more people are online and
then allows you to exchange messages or join a private chat room.

Netiquette, which
is short for Internet etiquette, is the code of acceptable behaviors users
should follow while on the Internet. Rules for e-mail, newsgroups, and chat
rooms include:
- Keep messages brief and use proper
grammar and spelling.
- Be careful when using sarcasm and
humor.
- Be polite and avoid offensive
language.
- Avoid sending flames (abusive
messages) and spam (unsolicited junk mail).
- Do not use all capital letters, which is
the equivalent of SHOUTING!
- Use emoticons (such as :) for
smile) to express emotion.
- Use abbreviations (such as BTW for by
the way) for popular phrases.
- Clearly identify a spoiler, which
is a message that reveals a solution to a game or an ending to a movie or
program.
- Read the FAQ (frequently asked
questions) document.
- Do not assume all material is accurate
or up-to-date.
- Never read someone’s private e-mail.
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