INTRODUCTION TO THE INTERNET. Presented by the Benbrook Public Library

Transcription

1 INTRODUCTION TO THE INTERNET Presented by the Benbrook Public Library

2 INTRODUCTION TO THE INTERNET What is the Internet? How did it come about? What is the World Wide Web? How does it work? How do I get connected? What does the Internet do for me?

3 What is the Internet? The Internet is a network of networks that connects tens of millions of computers from all around the world together.

4 What is the Internet? It is not owned, and therefore controlled, by any single government, company, or individual. In its present form, it is wide open and freely accessible to anyone with an internet connection (and unblocked by governing and/or commercial organizations) It is a nearly universal medium for human expression and interaction in all of its inspiring greatness and abject abuses.

5 How did it come about? The concept was first described in 1962 as an Intergalactic Computer Network. The National Physical Laboratory (NPL), on August 5, 1968, in the United Kingdom, was the first to develop packet switching, which formed the basis for moving data electronically.

6 How did it come about? What we now know as the Internet began as a way for universities and research laboratories conducting military research to securely and reliably exchange information over great distances. The first Internet was called Advanced Research Projects Agency Network (ARPANET) and was funded by the Defense Advanced Research Projects Agency (DARPA) of the United States Department of Defense.

7 How did it come about? By the early 1970 s the four universities in California, which formed the first true Internet were able to interact with universities on the East Coast. This Internet grew as more universities, and later businesses, adopted the technology for transferring and accessing their data over existing communications infrastructure.

8 What is the World Wide Web? The World-Wide Web, also know as WWW or W3, is a system of hypertext files designed to be accessed over the Internet by web browsers through hyperlinks. Files can be in many forms including text, images, sound recordings, and videos. Think of the Internet as infrastructure and the WWW as content.

9 How does it work? Information that has been digitized is divided into manageable packets and moved across the communications infrastructure in bursts at very high speeds. Think of a train and its system of railways and rail yards. The locomotive is the address packet which knows where the file is destined, the file is the complement of rail cars filled with various cargo, and the caboose is the final packet that accounts for all segments completeness along the way.

10 How does it work? Hypertext Transfer Protocol Hypertext transfer protocol (HTTP) is an application protocol that forms the basis for data interoperability across networks. HTTP defines how messages are formatted and transferred. It tells the web browser to find and fetch data from content servers

11 How does it work? Hypertext Markup Language Hypertext markup language (HTML) is Information is coded to display, arrange, and distribute, for collaborative interaction among users. This application tells the user s terminal what font, colors, file types, and layout to display per the original file s design.

12 How does it work? Web Browsers A web browser is a software application for retrieving, presenting, and traversing information resources on the World Wide Web. An information resource is identified by a Uniform Resource Identifier (URI) and may be a web page, image, video, or other data type. Hyperlinks enable users easily to navigate their browsers to related resources.

13 How does it work? Search Engines A search engine is an application that searches across the Internet for files matching keywords and returns a list of results. Content originators seek to optimize their placement at the top of the results by loading their metadata with keyword tags to help trick the search engine to rank its relevance to the search term higher on the results list.

14 How does it work? Each connection on a network has a specific address, given by the ISP, called an IP (Internet Protocol) address. Each networked device has a unique MAC address so information sent to a particular device can find it across the global network.

15 How does it work? Each information package has a location address called a URL (Uniform Resource Locator). Every URL consists of some of the following: the scheme name (commonly called protocol), followed by a colon, two slashes, a domain name (or IP address), a port number, the path of the resource to be fetched or the program to be run, then, for programs such as Common Gateway Interface (CGI) scripts, a query string, and an optional fragment identifier.

16 How does it work? This is an example of URL syntax: scheme://domain:port/path?query_string#fragment_id

17 How does it work? This is an example of a simple URL: This is an example of a complex URL: %3A%2F%2Fwww.ebay.com%2F Note the s in the http segment, and note that is does not include www in the address. Why is this?

18 How does it work? Web browsers and search engines greatly simplify users interaction with the web, which as we know contains billions of information resources. Simply type search terms in the search box using plain English and they return results ranked by relevance and probability.

19 How does it work?

20 How does it work? By using search strategies, users can browse for topics of interest, or target specific resources. For example, combining terms with Boolean logic will narrow results. mississippi AND river; automobile OR vehicle; this NOT that

21 How does it work? Domain Names denotes the owner of websites and its content Top Level Domain Name identifiers distinguish the type of website owner DOMAIN NAME.com.org.gov.edu.mil.us.uk.de.ru REGISTERED OWNER Commercial or business Non-profit organization Governmental agency (US) Academic institution Military (US) Country codes

22 How do I get connected? Connectivity The Internet can be accessed through the telephone lines, such as dial-up and DSL (digital subscriber line), dedicated lines, such as copper cable, fiber-optic, or wirelessly through Wi-Fi, cellular and satellite signals. Users must subscribe to an plan offered by an Internet Service Provider (ISP), with prices based on available media, speeds, coverage, and usage, and have the proper devices (usually purchased or leased by the ISP).

23 How do I get connected? Each type of connection has its own advantages and disadvantages. Type Advantages Disadvantages Dial-up Inexpensive No special equipment required Slow speed Requires physical connection over telephone landline DSL Faster speed Widely available Reliable connectivity Requires physical connection and adapter for telephone landline Cable - Copper Much faster speed Reliable connectivity Widely available in urban areas Not available in all rural areas Requires cable modem and physical connection

24 How do I get connected? Type Advantages Disadvantages Cable Fiber Optic Fastest and most reliable speed Becoming more available in new developments Higher cost Not available in rural areas and parts of urban areas Requires special cable modem and physical connection Wi-Fi Fast speed Widely available Free guest access Semi-reliable connectivity Requires wireless network adapter Must be in proximity to signal Less secure vulnerable to intruders Cellular Fast speed Highly mobile Semi-reliable connectivity Speeds vary with cell network Requires special adapter Costs are generally higher

25 What does the Internet do for me????? YOU NAME IT!!!

26 THANK YOU!