Communications, Networks, the Internet, and the World Wide Web Chapter 2

Learning Objectives Define communications (telecommunications) in the context of computer systems. Identify the basic components of a communications system. Describe how and why networked computers are used within schools and school districts. Explain what the internet is and how it works. List the major services on the Internet and explain how they work.

Learning Objectives Define the World Wide Web (WWW). Explain how a Web site delivers information. Demonstrate the ability to use WWW search tools. Demonstrate the ability to create a simple Web site (later in class) Describe the educational implications of the Internet and the World Wide Web Understand security and netiquette issues related to the Internet and the WWW.

Define Telecommunications The exchange of information over significant distances by electronic means. Examples of applications E-mail Telecommuting Videoconferencing Internet POTS Television Radio

What is a Communications Network? A communications network is a collection of computers and other equipment organized to share, data, hardware, and software. Networks also require communications software.

Communications Networks notebook computers Web-enabled PDAs smart phones servers GPS receivers desktop computers mainframe computers set-top boxes Tablet PCs

Communications Networks Local Area Networks (LAN) Covers limited geographical area Server manages resources Wide Area Networks (WAN) Covers large geographical area Can consist of several LANs

Networking the Classroom, School and School District. Limited Local Area Network (LAN) connecting computers, printers and other devices within the confines of the classroom.

Networking the Classroom, School and School District. Providing a network between the Classrooms Labs Library School Administrative areas. Outside world

Networking the Classroom, School and School District. Providing a network between the Schools Administrative Buildings Outside world

Wireless Networks (WAN) Provides access to networks without wire or cable. Most notebooks and other devices are coming with wireless capabilities. Most PC’s can be ordered with wireless network cards or they can be installed aftermarket. Great advantage in retrofitting a school.

Benefits of Networks in Schools Sharing of computer hardware, software, and data resources Access to educational resources Communicate with other educators and students

What is the Internet? The Internet is a worldwide collection of networks that link together millions of businesses, governments, educational institutions, and individuals. Each of these networks provides resources and data that add to the abundance of goods, services, and information accessible via the Internet.

A Brief History of the Internet The Pentagon’s Advanced Research Projects Agency (ARPA) begins a project to network computers around the country, ARPNET. 1969 The first computers are connected to the ARPNET 1972 The first e-mail is sent 1981 the IBM PC is introduced 1984 Apple introduces the McIntosh computer

A Brief History of the Internet 1989 Tim Bernes-Lee invents the World Wide Web 1992 Windows 3.1 is introduced 1993 a graphic interface for the WWW is created called Mosaic. This will become Netscape Navigator.

How the Internet Works - Connecting to the Internet Slow speed technology Dial-up access High speed technology Digital subscriber line (DSL) Cable television Internet services (CATV), Satellite Wireless Broadband Connection is always on

How the Internet Works – Services Provided E-mail File Transfer Protocol World Wide Web Streaming media Chat rooms and message boards. These services are called protocols in the computer world. A protocol is a standard procedure for regulating data transmission between computers

How the Internet Works – Services Provided WWW E-mail FTP Streaming Media

How the Internet Works – How Data is Sent Data is divided into packets Packets are sent across the Internet using various types of equipment Packets are reassembled at receiving computer.

How the Internet Works – The Structure Networks from private industry Telephone companies Cable companies Satellite companies Government

How the Internet Works – Three Main Parts Client Server Backbone Internet Cloud

How the Internet Works – Addressing The Internet Protocol Address or IP Address Known as the dotted quad xxx.xxx.xxx.xxx Number that uniquely identifies each computer or device connected to Internet Domain Name is the text version of IP Address www.amazon.com = 207.171.166.252

What is the World Wide Web? The World Wide Web, or simply Web, consists of a worldwide collection of electronic documents, Web pages, organized into Web sites.

The World Wide Web – the URL The Universal Resource Locator (URL) Unique address for a web page located on a specific web server. protocol domain name path http://www.nationalgeographic.com/travel/index.html

The World Wide Web – the Web Page Web pages consist of three components; Text Multimedia Graphics Audio Video Hyperlinks

The World Wide Web – Hyperlinks Text or graphics that connect (link) to other web pages. Three types of links Items found elsewhere on the same page Different web pages in the same site. Other web sites. Hyperlinks can be text or graphics

The World Wide Web – The Web Browser Web Browser Software Interprets HTML, displays Web pages and enables you to link to other Web pages and Web sites The two most popular browsers are; Internet Explorer FireFox

The World Wide Web – Downloading The process of transferring information for a server to a client Downloading information can be effected by a number of variables; Type of Internet connection ISP Time of day and day of week Amount of information to be downloaded.

The World Wide Web – Categories of Web Sites - Portal A Web site that offers a variety of services from one, convenient location, usually for free

The World Wide Web – Categories of Web Sites - News Contains newsworthy material Stories and articles relating to current events, life, money, sports, and weather News Archives

The World Wide Web – Categories of Web Sites - Informational Contains factual information Created by organizations and government agencies Make sure that the web site is legitimate

The World Wide Web – Categories of Web Sites - Advocacy Contains content that describes a cause, opinion, or idea

The World Wide Web – Categories of Web Sites – Business and Marketing Contains content that promotes products Allows you to purchase products or services online Allows companies to purchase goods and service from other companies

The World Wide Web – Categories of Web Sites – Education Offers avenues for formal and informal teaching and learning Colleges offer online classes and degrees Some companies offer online training for employees

The World Wide Web – Categories of Web Sites – Entertainment Offers an interactive environment featuring music, video, sports, games, and more

The World Wide Web – Categories of Web Sites – Personal Web page maintained by private individual Reasons: sharing life experience with the world or job hunting

The World Wide Web – Categories of Web Sites – Blog An informational Web site consisting of time stamped: Articles Posts In a diary or journal format.

The World Wide Web – Netiquette Netiquette is the code of acceptable behaviors users should follow while on the Internet. Golden Rule: Treat others as you would like them to treat you. Website for Netiquette information http://www.albion.com/netiquette/

The World Wide Web – Multimedia – Graphics and Images Three formats GIF - simple graphics JPEG - photographs PNG – new format Animate Graphics Animated GIFs Flash animations

The World Wide Web – Multimedia – Streaming Media A continuous stream of audio or video. Is always on and takes up band width for other internet uses.

The World Wide Web – Multimedia – Audio MP3 audio format Compresses audio to one-tenth of original size while preserving quality of sound Allows for transfer of music over Web

The World Wide Web – Multimedia – Video Consists of full-motion images with sound played back at various speeds MPEG is popular video compression standard Examples YouTube WebCams Movies

The World Wide Web – Multimedia – Virtual Reality Use of computers to simulate real or imagined environment Appears as a three dimensional (3-D) space

The World Wide Web – Plug-ins Programs that extend the capability of a browser You can download many plug-ins at no cost from various Web sites

The World Wide Web – E-commerce Short for electronic commerce Business transaction that occurs over the Internet Types of e-commerce Business to Consumer (B2C) Sale of goods to general public Consumer to Consumer (C2C) One consumer sells directly to another Business to Business (B2B) Business providing goods and services to other businesses

E-mail The transmission of messages and files via a computer network Messages can consist of simple text or can contain attachments, such as documents, graphics, or audio/video clips Internet access providers usually provide an e-mail program Some Web sites—such as MSN Hotmail and Yahoo!—provide free e-mail services

E-mail The e-mail address is a combination of samjohnson@scsite.com domain name user name samjohnson@scsite.com

E-mail How an e-mail message travels Internet POP 3 routers server outgoing mail server Internet routers incoming mail server POP 3 server

The World Wide Web – Security Firewall Filtering software Acceptable Use Policy (AUP)