internet principles of operation
DESCRIPTION
This slide is prepared for the students of O & A Level ComputersTRANSCRIPT
Computer Science 2210
Internet Principles of Operation
By Inqilab Ruknuddin [email protected]
www.ruknuddin.com
Objectives:
•show understanding of the role of the browser and Internet server•show understanding of what is meant by hypertext transfer protocol (http) and HTML•distinguish between HTML structure and presentation•show understanding of the concept of MAC address, Internet Protocol (IP) address and cookies
What is Internet?The Internet is a global system of interconnected computernetworks that use the standard Internet protocol suite toserve billions of users worldwide.It is a network of networks that consists of millions ofprivate, public, academic, business, and governmentnetworks, of local to global scope, that are linked by a broadarray of electronic, wireless and optical networkingtechnologies.Internet carries an extensive range of information resourcesand services, such as the inter-linked hypertext documentsof the World Wide Web (WWW) and the infrastructure tosupport email.
Client/Server Architecture
A network architecture in which each computer or processon the network is either a client or a server.Internet server (web server) is a special computer, on whichwebsites are stored. Web Server is constantly switched onand connected to the Internet so that each Internet useraround the world can access website at all times. Thiscomputer is built up with selected high quality components,which can endure incessant work and high load.Clients are PCs or workstations on which users runapplications.
Client/Server Architecture
Web Client
Web client is a computer, on which user actuallyworks. It has web browser to locate, retrieve anddisplay contents on web servers.The user logs onto a client computer which thenconnects to the server, verifies the user and thenallows them access to the files stored on the serverthat they have permission to access.
Web Browser
Web browser is a software application used to
locate, retrieve and also display content on the
World Wide Web, including Web pages, images,
video and other files.
The major web browsers are Firefox, Google
Chrome, Internet Explorer, Opera, and Safari
Web ServerWeb server is a special computer, on whichwebsites are stored.Web Server is constantly switched on andconnected to the Internet so that each Internetuser around the world can access website at alltimes.This computer stores:
WebsitesImages & VideosFiles
HTMLHTML is the "mother tongue" of your browser.
HTML (Hyper Text Mark-up Language) is theauthoring language, used to create web pages andother information that can be displayed in a webbrowser.The websites are developed in HTML and stored onWeb Servers. When User types the URL of website,browser locates and fetches the website fromserver on clients computer and displays contents.
HTTPHTTP (HyperText Transfer Protocol), the underlyingprotocol used by the World Wide Web. HTTPdefines how messages are formatted andtransmitted, and what actions Web servers andbrowsers should take in response to variouscommands. For example, when you enter a URL inyour browser, this actually sends an HTTP commandto the Web server directing it to fetch and transmitthe requested Web page.
ProtocolsA protocol is the set of rules that define how devices communicate.
how the communication will start the transmission speed the significance of the bits being transmitted how the bits will be delivered (one at a time or in
groups of 16 for example) error checking procedures used
The Internet Protocol is known as TCP/IP.
IP Addressing An Internet Protocol (IP) address is a unique 32-bit reference number that is allocated to devices on a computer network that uses the Internet Protocol. IP addresses are stored as 32-bit numbers 2^(32) = 4 billion possible unique IP addresses For our convenience IP addresses are usually displayed as a series of 4 decimal numbers, each one representing 8 bits of the original binary address. 32-bit binary version: 110010011010000001011011011111111 11001001 20110100000 16001011011 9101111111 127decimal version: 201.160.91.127 Some IP addresses are reserved for private network ranges e.g.
10.0.0.0 - 10.255.255.255 172.16.0.0 - 172.31.255.255 192.168.0.0 - 192.168.255.255
MAC Addressing In computer networking, a Media Access Control address (MAC address) is a unique 48-bit number assigned to a network interface card (NIC) to identify it on a LAN. Because they are so long, MAC addresses are usually displayed in hexadecimal. 48-bit binary version: 000000000000100101111100111100011111011110000101 hexadecimal version: 00-09-7C-F1-F7-85 MAC addresses are stored as 48-bit numbers 2^(48) = 281 trillion possible unique MAC addresses.
Cookies (HTTP cookie, web cookie, or browser cookie)
A cookie is a small piece of data sent from a website and stored in a user's web browser while the user is browsing that website. Every time the user loads the website, the browser sends the cookie back to the server to notify the website of the user's previous activity In computer networking.
