MICROCOMPUTER APPLICATION: THE INTERNET AND WORLD WIDE WEB

THE INTERNET AND WORLD WIDE WEB

What is the Internet?

• The Internet is a worldwide network of connected computers.

• This allows the sharing of electronic information and resources.

• The Internet is considered the LARGEST telecommunications system ever created.

• A common set of rules, known as protocols, allow the transport and viewing of files and documents found on computers connected to the Internet.

What is the World Wide Web?

• The World Wide Web (or WWW) is one part of the Internet.

The World Wide Web (WWW)

• The World Wide Web is a hypertext-based system.

• Hypertext allows users to click on buttons or highlighted text using a mouse to go to other Web pages containing text, sound, pictures, or video.

• The World Wide Web is accessed by the use of a web browser

Important terminology

• WEBSITE, also written as Web site,web site, or simply site, is a set of related web pages containing content (media), including text, video, music, audio, images, etc. A website is hosted on at least one web server, accessible via a network such as the Internet or a private local area network through an Internet address known as a Uniform Resource Locator. All publicly accessible websites collectively constitute the World Wide Web.

• Web page or webpage is a document or information resource that is suitable for the World Wide Web and can be accessed through a web browser and displayed on a monitor or mobile device. This information is usually in HTML or XHTML format, and may provide navigation to other web pages via hypertext links. Web pages frequently subsume other resources such as style sheets, scripts and images into their final presentation.

• Web pages may be retrieved from a local computer or from a remote web server. The web server may restrict access only to a private network, e.g. a corporate intranet, or it may publish pages on the World Wide Web. Web pages are requested and served from web servers using Hypertext Transfer Protocol (HTTP).

• Web server can refer to either the hardware (the computer) or the software (the computer application) that helps to deliver content that can be accessed through the Internet

• The most common use of web servers is to host web sites but there are other uses such as data storage or running enterprise applications.

Web Browsers

• A browser lets you access the WWW and “browse” the Internet for information.

• You use the browser to maneuver through web pages.

Parts of a Web Browser

• Title Bar: Lists the title of the web page that you are viewing. There are three buttons to the right of the title bar which reduce, maximize, or close the screen.

• Content Area: Displays the current web page that is open on the browser.

• Address Field: Shows the URL (Web address) of the web page that is currently displayed.

• Status Indicator: Shows whether or not the Web page has completely loaded and can be viewed.

• Progress Bar: Indicates how much of the web page has loaded for viewing.

• Status Message Field: Tells you the status of the web page. Indicates when the web page is done and open for viewing.

• Scroll Bar: This is used to move up or down on the web page.

Web Browsers

• A browser “reads” the WWW pages, which are written in Hypertext Markup Language (HTML), and converts them into a readable form.

• To look at an example of HTML, click the VIEW menu at the top of a browser screen. This brings down a sub-menu screen. Click on SOURCE. After viewing, click on X (the close screen button) to close the source box.

The Library’s Home Page

This is an example of a World Wide Web (WWW) page.

Web Addresses

http://library.sullivan.edu/ is an example of a web address (also known as a Uniform Resource Locator or URL)

• Every web page must have an unique web address to be found on the Internet.

Uniform Resource Locators (Web Addresses)

• Your browser uses the web address (URL) to find information located on another computer and to retrieve the corresponding page situated on that server.

• Each part of the URL directs the browser to the correct web page.

Different Domains on the WWW

.com - commercial

.net - network

.edu - educational

.org - organization

.gov - government

How to Access Web Pages

Here are three ways to access a web page:

1. Type the Uniform Resource Locator (URL) in the address box.

2. Click on hypertext links on a web page.

3. Use a search tool such as a keyword search engine or web directory.

How to Access Web Pages: Type the URL in the Address Box

• Type the Uniform Resource Locator (web address) in the browser address box.

• Click GO (or press the ENTER button on the keyboard).

• The web address must be correct (no misspellings, extra spaces, etc.) to go to the correct web page.

How to Access Web Pages: Click on Hypertext Links

§ Hypertext links on a web page lead to other web pages.

§ The links on a web page are usually highlighted, underlined, or are pictures.

§ When you place the mouse cursor over a link, the arrow will change into a hand.

§ Click on the link to go to another web page.

§ Use your BACK button to return to the original web page.

How to Access Web Pages: Use a Search Tool

§ Search tools help you find information on the WWW.

§ No single search tool finds every web site or web page in existence. Different search tools search different and overlapping parts of the web.

§ Examples of search tools include:

Google

AltaVista

Yahoo!

Lycos

Hypertext Documents

Electronic Mail (e-mail)

• The Internet system works because of SMTP, Simple Mail Transfer Protocol. SMTP is part of the TCP/IP suit of protocols.

• SMTP is a protocol, or set of rules that enables electronic mail to move smoothly through the internet. Because of SMTP, a UNIX machine can send mail to a PC or Macintosh computer and vice versa.

• Electronic mail has revolutionized the way people communicate when they cannot talk in person. No longer must people wait for traditional postal mail delivery. On the internet, if both the sender and the receiver log on frequently, it is possible to exchange several messages with someone in a single day.

• You can communicate with anyone in the world who has an internet address or email account with a system connected to the internet. All you need is access to the internet and an e-mail program.

• A Typical e-mail message has three basic elements; header, message, and signature.

• The header appears first and typically includes the following information:

• Subject: A one-line description, used to present the topic of the message. Subject lines typically are displayed when a person checks his or her mailbox.

• Addresses: addresses of the persons sending (to: ), receiving (from: ), and,

• Optionally, anyone else who is to receive copies (CC and BCC).

Email

• Attachments:

• Many e-mail programs allow you to attach files such as documents and worksheets. If a message has an attachment, the file name appears on the attachment line.

• (b) The letter or message comes next. It is typically, short and to the point.

• (c) Finally, the signature line provides additional information about the sender. Typically, this information includes the sender’s name, address, and telephone number.

E-MAIL ADDRESSES

• The Internet uses an addressing method known as the Domain Name System (DNS) to assign names and numbers to people and computers. This system divides an address into three parts: user name (ID), domain name, and domain code. For example takiluki@zanlink.com: user ID is takiluki, domain name is zanlink and com is the domain code which is commercial

• The domain code identifies the geographical description or organizational identification.

• Almost all ISPs (Internet Service Providers) and online service provides offer e-mail service to their customers. But you can get this service for free from different service providers such as Hotmail, USA Net Inc., and Yahoo.

• To learn more about free e-mail service, visit one or more of the following sites: http://www.hotmail.com, http://www.usa.net, mail.yahoo.com etc.

INSTANT MESSAGING

• Like a chat groups, an instant messaging allows one or more people to communicate via direct, “live” communication. Instant messaging, however, provides greater control and flexibility than chat groups.

• To use instant messaging, you specify a list of friends, or “buddies”, and register with an instant messaging server. Whenever you connect to the internet, you use special software to tell your messaging server that you are online too. It notifies you if any of your buddies are online.

• At the same time, it notifies your buddies that you are online. You can then send messages back and forth to one another instantly.

What are social networking sites?

• A way to meet people

• A way to introduce yourself to the world

• A way to let the world know how weird you are

• A way for child molesters to find prey

• My Space

– http://www.myspace.com/

• Facebook

– http://www.facebook.com/

• Linked-In

– http://www.linkedin.com/