Answer to Question #300861 in Programming & Computer Science for Tege

Question

9. Write short notes on:

a) Electronic mail

b) voice over IP

c) HTTP

d) FTP

Answer 1

a) Short for electronic mail, e-mail or email is information stored on a computer that is exchanged between two users over telecommunications. More plainly, e-mail is a message that may contain text, files, images, or other attachments sent through a network to a specified individual or group of individuals. E-mail is user to user communication. E-mail communication is user to user via the computer. We can get the advantage of privacy from e-mail as the mail is delivered to an individual’s mail box which can be accessed or opened only by the intended recipient. E-mail is a cheaper communication as messages can be transmitted within seconds electronically without using any paper. 

b) Voice-over-Internet protocol (VoIP) is a technology that lets users make calls using a broadband Internet connection instead of a standard phone line. VoIP technology converts the voice signal used in traditional phone calls into a digital signal that travels via the Internet rather than analog phone lines. Some VoIP services allow you to call people using the same service, but others may allow you to call anyone. They can have a telephone number – including local, long-distance, mobile, and international numbers or not. Some VoIP services only work over your computer or a special VoIP phone while other services allow you to use a traditional phone connected to a VoIP adapter. 

c) HTTP stands for Hypertext Transfer Protocol. It is used to access data on the WWW (World Wide Web). It is a protocol which governs the communication between the client and server.

There are three important features of HTTP:

i. HTTP is Connectionless

After a request is made, the client disconnects from the server and waits for a response. The server must re-establish the connection after it processes the request.

ii. HTTP is Media Independent

Any type of data can be sent by HTTP as long as both the client and server know how to handle the data content.

iii. HTTP is Stateless

This is a direct result of HTTP being connectionless. The server and client are aware of each other only during a request. Afterwards, each forgets the other. For this reason neither the client now the browser can retain information between different requests across the web pages.

Working:

i. A browser contacts a server to establish a TCP connection with it.

ii. The HTTP software on the client sends a request to the server. The HTTP software on the server interprets this request and sends the response to the client.

iii. HTTP Commands:

• GET : Request by a client to obtain a web page from the server.
• PUT : Request by a client to store a web page on the server.
• POST : Request by a client to update contents of a web page on the server.
•  DELETE: Request by a client to remove a web page from the server.

d) FTP stands for File transfer protocol. · 

• FTP is a standard internet protocol provided by TCP/IP used for transmitting the files from one host to another.It is mainly used for transferring the web page files from their creator to the computer that acts as a server for other computers on the internet.
• It is also used for downloading the files to computer from other servers.
• It provides the sharing of files.
• It is used to encourage the use of remote computers.
• It transfers the data more reliably and efficiently.