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Networks and the Internet

PCS115 Introduction to the Internet©Richard L. Goldman

December 7, 2006

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What is a Network?

Two or more computers connected together.

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A Network

Server Network

Printer

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What is the purpose of a network? Allows people on the network to share information.

Data files Pictures Music ?

Allows people on the network to share resources. Printers Scanners Programs ?

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Connection to the Internet (Home Model)

Internet

Modem

Personal Computer

Printer

Internet Service Provider

(ISP)

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Connection to the Internet (Business Model)

Internet

(ISP) Router

Server Network

Printer

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What is the Internet?

A large number of networks as well as individual computers connected together.

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What is the World Wide Web? A system that allows people to easily

navigate through the Internet (using hyperlinks) and view documents.

The WWW uses a computer language called HTML that all computers can read.

HTML stands for: Hypertext Markup Language.

Developed at the CERN in 1989 by Timothy Barners-Lee.

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What is a link (Hyperlink)?

A link is an object (usually a word, phrase, or picture) that contains the Internet address of another location on the Internet.

When you click on the link it takes you there.

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What is a Web Page, a Web Site, Home Page, and a Web Server? Web Page – A Hypertext document. Web Site – A collection of web pages. Home Page –

The browser “Start Page” A page about a person or organization The first web page of a web site.

Web Server – The computer that holds web sites.

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What are Newsgroups?

Newsgroups are forums on specific topics where comments or questions are posted.

Other people reading the comments or questions may respond to them.

You may check back later to see what responses you may have received.

Newsgroups are often very useful.

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What are Chat Rooms?

Chat rooms are live discussion groups on the Internet.

They may be started by anyone on any topic (or no topic at all).

Any one may view or join in. Some are moderated but many are not. They are often strictly for entertainment. Creditability is a major problem.

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What is an Internet Service Provider (ISP)? A company that provides access to the

Internet through their computers. Examples:

America On Line (AOL) – national Valley Internet Company – Local

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What is a Browser?

A program on your computer that can retrieve and display hypertext documents found on the Internet.

Browsers: Microsoft; Internet Explorer Netscape; Navigator Oracle; Power Browser Opera Software; Opera

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Home Page

The page that appears when you start a browser.

Can be set by: IE 4 – View/Internet Options/Home Page IE 5 – Tools/Internet Options/Home Page IE 6 – Same – Currently used by most Users IE 7 – Click button then select “Add or change

home page” Can return to it at any time by clicking the

Home button on the Standard Toolbar.

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Toolbars (View menu/Toolbars)

IE 5

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Toolbars

Menu Bar

Standard ToolBar

Address Bar

Title Bar

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Toolbars

Status Bar

Links Bar

Task Bar

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Title Bar

Identifies active Web page.

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Menu Bar

Access to commands and options. File Edit View Go or Favorites Help Tools

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Standard Toolbar Buttons for common commands.

Back Forward Stop Refresh Home Search Favorites History Channels Fullscreen Mail

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Address Bar

Contains an Address Box to enter the address of the Web page that you want to view.

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Links Bar

A place to put links to your favorite sites.

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Status Bar

Shows: Target of link Status of Search and load activity Progress of page completion (Progress Bar)

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URLUniform Resource Locator

http://www.northern.edu/data/programs.html

Protocol:http = Hypertext Transfer ProtocolUsed to transfer html documents.

ftp = File Transfer ProtocolUsed to transfer whole files.

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URLUniform Resource Locator

http://www.northern.edu/data/programs.html

Server Address:Name of computer (including the Domain Name Type code) that contains the data you are seeking.

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URLUniform Resource Locator

http://www.northern.edu/data/programs.html

Domain Types (or Top Level Domains):The original 7 U.S. Internet Domain types.

edu educationcom commercialorg nonprofit organizationsgov governmentnet network host or gateway orgsint Internet organizationsmil military

Two letter country codes are used outside of the United States.

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URLUniform Resource Locator

http://www.northern.edu/data/programs.html

Folder (subweb or subdirectory):The folder on the server that contains the file that you are looking for.

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URLUniform Resource Locator

http://www.northern.edu/data/programs.html

File Name:The name of the file.

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URL’s

Most URL’s are lower case, however some contain Upper case letters.

URL’s may be case sensitive and must be typed in without deviation.

Redirection, automatic forwarding, and other techniques allow some variation on popular sites.

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DNS – Domain Name Server

Converts: URL (Universal Resource Locator) into DDNS (Dotted Decimal Number System) (IP address)

www.northern.edu = 129.70.5.101

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Printing

Screen size and page size don’t match. The browser may adjust content to fit the page.

Select what you want and print the Selection. Select and copy what you want and paste it into

a word processor. Edit it and print it from there. Use Adobe Acrobat Reader files (.PDF) if

available. Laser printed pages usually cost 1-3 cents per

page. Bubble jet printed pages usually cost 7-15 cents

per page.

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Help

Contents Like the table of contents of a book. It shows you a view of

the topics covered in Help. Index (Key words)

Like the index of a book, just type in the word you are looking for.

Search Gives you the ability to search for any word that might

appear in the Help documentation.