INTERNET

Objectives

• Explain the origin of the Internet and describe how the Internet works.

• Explain the difference between the World Wide Web and the Internet.

• Describe the major features of the Internet.• Explain how to connect to the Internet.

Objectives (cont.)

• Describe a browser.• Identify browser features.• Apply and use browser features.• Describe other Internet features.

Evolution of the Internet

• Early origins– Can be traced to the 1960s– U. S. Department of Defense– Original name was ARPANET– Steady growth over the next few years

Evolution of the Internet (cont.)

• In 1990, ARPANET ceased to exist.• The World Wide Web came into existence in

1992.• Mosaic, the first browser, was released in

1993.– A 340% growth in number of users

Internet Continues to Grow

Impact on Society

• In 2005, over two-thirds of all Americans used the Internet.

• The benefits are numerous and widespread.– Businesses and individuals benefit.– Disabled also benefit.

Top-Level Domain Abbreviations

Accessing the Internet

• Getting connected– Connect from home, school, or business– Requires an ISP– Communications software– Web browser

Connecting to the Internet

What Is the Web?

How the Web Works

Web Pages

Websites

Web Browsers

Connecting to the Internet

Making Connections

To go online your computer must be equipped with a modem, a device that translates the digital signals from your computer into analog signals that travel over a standard phone line.

About Modems

Modems were invented to convert digital computer signals into a form that allows them to travel over phone lines.

Modem stands for MOdulator/DEModulator.

DSL

DSL (Digital Subscriber Line), a high-speed or broadband technology, has become increasingly popular. A DSL line remains connected to the Internet.

Data is downloaded to your computer at rates up to 1.544 Mbps and you can send data at 128 Kbps.

DSL service requires a digital modem and a network card in your computer.

a vast computer network linking smaller computer networks worldwide.

What Is the Web?

The World Wide Web is a collection of electronic documents that are linked together like a spider web.

These documents are stored on computers called servers located around the world.

The Web has evolved into a global electronic publishing medium and increasingly, a medium for conducting electronic commerce.

How the Web Works

Web pages are stored on web servers located around the globe.

Entering the (Uniform Resource Locator) URL of a web page in your web browser or clicking a link sends a request to the server which hosts the page.

The server sends the web page to your computer and your web browser displays it on your screen.

Web Pages

A web page (such as the one you are looking at now) is an electronic document written in a computer language called HTML (Hypertext Markup Language). 

Web pages can contain text, graphics, video, animation, and sound, as well as interactive features, such as data entry forms.

Each page has a unique address known as a URL (Uniform Resource Locator), which identifies its location on the server.

Websites

A website is one or more web pages that relate to a common theme, such as a person, business, organization, or a subject, such as sports.

The first page is called the home page, which acts like an index, indicating the content on the site.

From the home page, you can click hyperlinks to access other web pages.

Using Web URLs

URL (Uniform Resource Locator) indicates where the web page is stored on the Internet.

You need to type a URL exactly for your browser to locate the desired web page.

Some large websites have multiple URLs that access the same site. 

The location box or address field on your browser indicates the URL of the page you arrived at after clicking a link.

Examples of URLs

ftp://rtfm.mit.edu/pub/A directory of files at the Massachusetts Institute of Technology (MIT) that you can download

http://www.learnthenet.comThe home page for the Learn the Net website

news:rec.gardens.rosesA newsgroup about rose gardening

Web Browsers

A web browser is a software program used to access the World Wide Web.

A browser (also known as client software) retrieves data from remote web servers and displays a web page.

The two most popular browsers come from Netscape and Microsoft.

Browsers basically work the same way. Once you know one, you can easily learn the other.

Multimedia on the Web

Sound, video, animation, and 3D interactive video are referred to as multimedia.

Some multimedia, called streaming media, plays as soon as you access a web page.

Others require that you download the multimedia file to your computer first.

Multimedia files often requires that your browser use a plug-in program.

Plug-Ins

Plug-ins are small software programs that extend the capabilities of your browser by enabling it to play sounds and video clips or do other functions, such as automatically decompressing files that you download.

Plug-ins may come with your browser software or can be downloaded from websites.

Some plug-ins enable streaming audio or video, which lets you hear or view a multimedia file before it has completely downloaded to your computer.

Other Internet Services

• Blog or Web log• Chat rooms• Instant messaging• Mailing lists• Newsgroups and bulletin boards• Online conferencing• File Transfer Protocol

Summary

• No one person or organization can claim credit for creating the Internet.

• Origins of the Internet can be traced to the United States Department of Defense.

• The original name for the Internet was ARPANET.

• Mosaic was the Internet’s first graphical interface.

Summary (cont.)

• To connect to the Internet from a business, school, or other organization, you probably have a direct connection via a local area network and a network interface card.

• Types of Internet connections include modem and telephone line, DSL, cable modem, wireless, and fiber optics.

Summary (cont.)

• To connect to the Internet, you need an Internet connection, telecommunications software, and a browser for the Web.

• Interoperability means that all brands, models, and makes of computers can communicate with each other.

• A protocol is a standard format for transferring data between two devices.

Summary (cont.)

• TCP/IP is the agreed upon international standard for transmitting data.

• The domain name identifies a site on the Internet.

• The Internet is made up of many services.• The Web is an application that makes use of

the Internet.

Summary (cont.)

• Web pages can be linked through hyperlinks.• Microsoft Internet Explorer is a popular Web

browser.• The HTTP protocol defines how Web

messages are formatted and transmitted.• A Web site address is referred to as the URL

or Universal Resource Locator.

Summary (cont.)

• Every Web page on the Internet has its own unique address.

• HTML is a protocol that controls how Web pages are formatted and displayed.

• A Web page is coded with HTML markup tags.

Summary (cont.)

• Other Internet services include blogs, chat rooms, instant messaging, mailing lists, newsgroups, bulletin boards, online conferencing, and FTP.