Week 1 Know How The Internet Operates And The Facilities Available BY Bobtail Know how the internet operates and the facilities available: How the internet works Week 1 1. Introduction How can businesses use internet To Advertise To Communicate To Entertain To Inform To Publish To Recruit To Research TO sell To Support To Train It is predicted that users will use the internet in the near future to do all their businesses such as On-line buying Information search You need to know how servers and Internet service providers link together And how these links conform to different protocols 2.
How the Internet works Twenty or thirty years ago you could walk into a public library to find information on almost any subject you wanted Nowadays We can sit down at practically any computer, Almost anywhere on the planet, and Access an online information library far more powerful than any public library on Earth The World Wide Web The Web was invented less than 20 years ago Has been a huge popular success One of the greatest Inventions of all time 2. 1 What is deference between internet and the web? Common mistake to confuse the worldwide web (WWW) and Internet Internet existed for over 50 years
It is the “web” that makes internet important to use The basic techniques enable computers to talk to each other Internet made up of thousands of networks worldwide No one in charge of Internet – No governing body Internet backbone owned by private companies The word internet come from – Interconnected networks The Internet is a worldwide network of computers Linked mostly by telephone lines The Web is Just one of many things (called applications) that can run on the Internet When you send an email, you’re using the Internet When you chat to someone online, you’re most likely using the Internet too When you update a blob or Google for information to help you write a report, you’re using the Web over the Net 2. 3 What does the internet do? The Internet has one very simple Job: to move computerized information (known as data) from one place to another The machines that make up the Internet treat all the information they handle in exactly the same way Internet works like the postal service Letters are simply passed from one place to another, no matter who they are from or what messages they contain The same applies to the Internet 2. The web The Web is the worldwide collection of text pages, digital photographs, USIA files, videos, and Animations What makes the Web so special is the way all this information is connected together The basic building blocks of the Web are pages of text -?Web pages Computers on the internet are not linked to a “mega-computer” which holds all the information Within the network – some computers hold some information We need to access those information Collectively, all the world’s linked-up computers are called the Internet This arrangement is known as “client-server” architecture A collection of Web pages on the same computer is called a website Every web page has highlighted phrases allied links (or hypertext links) Clicking one of these takes you to another page on the website or another website entirely 2. 5 The internet and World Wide Web Computer network Any technology that allows people to connect computers to each other The Internet A large system of interconnected computer networks spanning the globe World Wide Web 2. Connecting to internet Requirement A computer or PDA or cell phone An account with an ISP (Internet Service Provider) A modem (modulator/demodulator) for dial-up services or a NICE (Network Interface Card) for DSL/Cable services Home network (Single network) Home network (multiple machines) Home wireless network 3. Servers and clients Server – Computers offering services Clients – Computers requesting information Internet works on basis that some computers act as servers These computers offer services for other computers that are requesting information Specialization: Clients specialize in user interface Servers specialize in managing data and application logic Sharing: Many clients can be supported by few servers Often data and logic are shared among applications and users 3. 1 Browsers Any user is able to connect to the internet You need to use a browser A browser is software that is used to access the internet
Navigating the Internet through a series of links the user is able to browse the Internet A browser lets you visit websites and do various activities like login, view multimedia, link from one site to another, visit one page from another, send and receive email The most common browser software titles on the market are: Microsoft Internet Explorer, Google’s Chrome, Maxilla Firebox, Apple Computer’s Safari, and Opera Each browser has a navigation toolbar This navigation bar is the most essential portion of the browser Browser availability depends on the operating system your computer is using Microsoft Windows, Linux, Bunt, Mac SO Browser needs to read Hypertext Markup Language (HTML) This code was created by Tim Burners-Lee 3. 2 HTML HyperText Markup Language It is not a programming language. Cannot be used to describe computations. Use to describe the general form and layout of documents to be displayed by the browser.
HTML is a very simple language used to “describe” the logical structure of a document Information from internet You can get the following from the internet: Written documents Catalogues Multimedia presentations Photo’s Videos Music Email 3. 3 Different servers Web servers The term web server can refer to either he hardware (the computer) or the software (the computer application) It helps to deliver web content that can be accessed through the internet Email servers Outgoing mail servers and Incoming mail servers Outgoing mail servers are known as ESMTP, or Simple Mail Transfer Protocol, servers Incoming mail servers come in two main varieties.
POP and MAP POP, or Post Office Protocol, version 3, servers are best known for storing sent and received messages on PC’s’ local hard drives ‘MAP, or Internet Message Access Protocol, servers always store copies of messages on servers Application servers Also called an appeasers, Handles all application operations between users and an organization’s backbend business applications or databases. An application server is typically used for complex transaction-based applications. 4. Types of connection to internet There are different ways to connect to the internet Most important is the speed that you can connect and download Two ways – modem or broadband 4. Modem Modem – Modulator demodulator A ASK modem or KIDS Modem use analogue connections – phone lines Dial a number to secure a connection Modem converts the analogue signal into digital format This allows computer to understand it Transmission process Modulation – Computer digital signals converted to analog Sent over analog phone line Demodulation – Analog signal converted back to digital ASK modem A ask modem is capable of download speeds up to cubit/s (56,000 bits per second) In the late sass, they were the most popular access method for personal Internet usage Their use has declined since the availability of broadband internet (DSL) and 4. Broadband Digital subscriber line (DSL, originally digital subscriber loop) is a family of technologies that provide internet access by transmitting digital data over the wires f a local telephone network The term broadband refers to the wide bandwidth characteristics of a transmission medium and its ability to transport multiple signals and traffic types simultaneously G is the fourth generation of mobile phone mobile phone communication technology standards More and more people switch to broadband Broadband gives “permanent” “always on” connectivity There is no need to dial a Broadband connections carry more data at a faster rate Popular for home and business use 5. Internet service provider (ISP) An ISP sells Internet access to companies and individuals. It provides web servers which connect to the Internet.
An ISP will provide it’s customers with a wide range of services.. Telephone services Bandwidth options. Email service. Web Hosting. Online and Telephone assistance. . Cable Television/ Need an account with the ISP and software that links with TCP/IP Examples of ISP Internet Service Provider Web Address AT&T worsened service wry. Tat. Com Digit, Inc. Www. Digit. Net GET Interlinking wry. Get. Net IBM Internet Connection www. IBM. Net MIMIC Internet wry. Mimicry. Com Entice On-Line Communication Services wry. Entice. Com Seines, Inc. wry. Seines. Com Sprint Internet Services wry. Sprint. Net I-Junket Technologies, Inc. wry. s. U. Net 5. Protocols Set of rules governing the exchange of data It is a way that computers “speak” to each other Assists with coordination of communications Was message received properly Important protocols include: Internet protocol (P) Transmission control protocol (TCP) Other protocols build on the foundation established by the TCP/IP protocol suite Simple Mail Transfer Protocol (ESMTP) File Transfer Protocol (FTP) Telnet TCP/IP IP stands for Internet Protocol IP software deals with the routing of packets through the maze of interconnected networks to their final destination TCP stands for Transmission Control Protocol TCP software breaks messages into packets, hands them off to the IP software for delivery, and then orders and reassembles the packets at their destination 5. 2 Internet protocol (P) Establish a unique name for every computer Each host needs an IP address IP address (ten digit number) A 32-bit number, arranged in 4 numbers separated by “. Example – 216. 24. 62. 133 Each number separated by a point is called an “octet” This number identifies the network, host and organization on the internet 5. Transmission Control Protocol (TCP) IP addresses let internet find the right way or route for a message Let you get the assuage to where you want it TCP takes the message and break it down into “packets” That is from origin (you) to destination TCP checks for errors and reassembles at other end Transport system that sort sentences or images out Ensures delivery of sensible text or images across internet TCP puts text or images back in proper order at other end Together TCP/IP makes internet work Example (Sending an email) TCP breaks it down as: The eat sandwich a man TCP sends: The sandwich eats a man 5. 4 Hypertext Transfer Protocol Function of HTTP is to specify in which way browsers and web servers transmits data o each other Establish which computer speaks first The transfer protocol is the set of rules that the computers use to move files from one computer to another on the Internet. The most common transfer protocol used on 6.
Domain names Most web browsers do not use the IP address t locate Web sites and individual pages. They use domain name addressing. A domain name is a unique name associated with a specific IP address by a program that runs on an Internet host computer. This program, which coordinates the IP addresses and domain names for all computers attached to it, is called DNS (Domain Name System ) software. The host computer that runs this software is called a domain name server. Domain names can include any number of parts separated by periods, however most domain names currently in use have only three or four parts. Domain names follow hierarchical model that you can follow from top to bottom if you read the name from the right to the left.