E-Mail And Internet (1 Day) Course

Ø Introduction Internet, E-mail, Protocol                          

Internet: The internet is a “network of networks”.  It is  a global collection of high powered computers that are connected to each other with  network cables telephone lines, microwave dishes, satellites etc.

Server:  Computer storing documents, sound files, video clips, program files, electronic shopping centres, animations, pictures, interactive contents and other information and presenting them electronically to others on net are known as servers.

Gateway: A Gateway is a communication device or program that pases data between networks having similar funtions but dissimilar implemetations.

Ineternet Service Providers(ISP):  ISP is a interenet service provider on periodical charges and/or installation charges.  Serial Line Input Protocol(SLIP) or Point to Point Protocol (PPP) is used for connecting internet.  This allows the users to surf without any intervention of the ISP servers.  TCP/IP connection internet must have PPP and SLIP protocols.

Modem: (Modular/Demodular) Modem is a device to translate the digital signals to analog and vice versa.  (Integrated Services Digital Network) ISDN is a digital telephone network which provides fastest internet for the users.

How Internet Works :  Once you send the mail.  The user and the Recipient may be on different networks, its like calling a local telephone number and asking for the area code.  The exact IP Address may be away from the User.  There may be many networks which the user mail has to cross to reach the recipient.  The email is broken into many pieces and sent in many packets, routers will redirect the packets to the destination.  The mails while passing through networks are stored in different places with a table of contents & addresses, and sent at their leisure.

WWW: Berner Lee is known as father of Word Wide Web.  It’s a consortium. 

Search Engines:  Search engines provide the information based on certain keyword/keyword combination.  Ex : Google.com, infoseek.com, altavista.digital.com, cyber411.com.

Helper Application:  Helper applications are small programs which take little space in the memory of your computer to play certain files, audio, video, etc on your system.  They will be downloaded by the browser automatically and play the file on your system. Ex: Quick Time, Real Player etc.

Types of Emails : 

(a)                     Web Based Free E-Mail  These mails are free on the net, but you have to bear with the advertisements they pose.  Ex. Google, yahoo, hotmail etc.

(b)                    Internet – Based Forwarding Services  NetForward.com is an example, which will allow you give all your emails of different free-email services and get one email and address from them so that you can attend to all the emails with one ID and Password.

(c)                     E-mail Service Providers  They are superior in quality of service and solutions.  ESPs use X.25 or X400 protocol for email. Return confirmation, prioritization of mails are few advantages of this system.  Charges are made as per the volumes of mails.

(d)                    Email through Internet Service Provider:  This is known as Gateway Internet Service, generally based on Unix and text based mails.

Protocol : A protocol is a set of rules to be followed while communicating with other computers.  The protocol mentions the style of bits on net for lower levels(the bit sequence for reading information)  and exchange for high level application programs (the way two programs send a file on net).

TCP/IP(Transmission Control Protocol/Internet Protocol) is a collection of protocols.  It uses five layers of the ISO/OSI model (International Standard Organization’s Open System Interconnect). ISO/OSI model defines (1) Application (2)Presentation (3)Session (4) Transport (5) Network (6) Data Link (7) Physical layers.

HTTP (Hyper Text Transmission Protocol) is web Native Protocol.

SLIP(Serial Line Internet Protocol) and PPP(Point to Point Protocol) are used by ISPs to connect their users on their servers. 

POP (Post Office Protocol) & SMTP(Simple Mail Transport Protocol) are two protocols used for mail services.

FTP (File Transfer Protocol) is a protocol used for transferring files on net.  To transfer files using FTP, one needs a client program and a server program.  FTP server is a program on a computer which will assist the files to be downloaded to client computer. Its like an online library.  Windows provides a program for FTP called ftp.exe. Type ftp in the run command from start button.  WSFTP is also a program which allows to upload files to a server.

Protocols for EMail: There are two mail protocols POP(Post Office Protocol) and SMTP(Simple Mail Transfer Protocol).  All the ISPs have POP and SMTP servers for maintaining emails.

WWW consortium is a combination of private industries and universities that work together to guide technical development of the Web and set the web standards.  RFC(Request For Comments) is one way how you can get information about internet.  Each RFC has a number to address.