Fundamentals of Internet

Internet Definitions

Internet: The Internet, sometimes called simply "the Net," is a worldwide system of computer networks - a network of networks in which users at any one computer can, if they have permission, get information from any other computer (and sometimes talk directly to users at other computers).

Types of Internet connection:

Dialup : Dialup connection is capable of a maximum speed of 56kbps and is sometimes referred to as Narrowband accordingly. It’s a slow connection. In DUP phone line is connected to the modem( internal \ external ). For the period Internet is on we can’t use the Telephone line to make \ receive calls.

Broadband : The term 'Broadband Internet', in simple terms, translates to 'High Speed Internet'. A high speed internet connection is generally anything with a download speed faster than 56kbps.It is also called as "Always on connection ". Also in this type of connection we can use Phone line while connected to internet simultaneously.

Types of Broadband:

ADSL (Asymmetric Digital Subscriber Line): Upload & Download speed are different.
SDSL (Symmetric Digital Subscriber Line): Upload & Download speed are same.
CABLE (Fibre Optic Cable) is the second most common broadband product.
WIRELESS – A new, but fast growing technology connects you to the Internet without any physical (cable or wire) connection.
SATELLITE – 2-Way Satellite Internet doesn't depend on land-based phone lines or cables, it can reach places that are far beyond the range of Broadband ADSL or Cable services.

Network: An interconnected system of computers that can communicate with each other and share files, data and resources.

Types of Network :
Local-Area Networks (LANs):
LAN, computers are connected together within a "local" area (for example, an office or home).

Wide-Area Networks (WANs):
In a WAN, computers are farther apart and are connected via telephone/communication lines, radio waves, or other means of connection.

ISDN:
ISDN, which stands for Integrated Services Digital Network, is a system of digital phone connections, which has been available for over a decade. This system allows voice and data to be transmitted simultaneously across the world using end-to-end digital connectivity.

Router:
A device that forwards data packets along networks. A router is connected to at least two networks, commonly two LANs or WANs or a LAN and its ISP’s network.
Routing is a process preformed by a router which moves packets of data around the Internet.

Switch:
Multiport Ethernet device designed to increase network performance by allowing only essential traffic on the attached individual Ethernet segments. Packets are filtered or forwarded based upon their source and destination addresses.

Hub:
A hub is a box that is used to gather groups of PCs together at a central location with cabling.

IP Address:
An identifier for a computer or device on a Network.

NIC:
Network Interface Card, an adapter card that is inserted into a computer, and contains the necessary software and electronics to enable the computer to communicate over the network.

Server :
A computer that provides resources to be shared on the network, such as files (file server) or terminals (terminal server).

Protocols:Network protocols are standards that allow computers to communicate. A protocol defines how computers identify one another on a network, the form that the data should take in transit, and how this information is processed once it reaches its final destination.



World Wide Web:
The World Wide Web (abbreviated as the Web or WWW) is a system of Internet servers that supports hypertext to access several Internet protocols on a single interface.

TCP :
The Transmission Control Protocol (TCP) is one of the core protocols of the Internet Protocol Suite. TCP provides reliable, ordered delivery of a stream of bytes from one program on one computer to another program on another computer.

IP :
The Internet Protocol (IP) is a protocol used for communicating data across a packet-switched internetwork using the Internet Protocol Suite (TCP/IP).
It has the task of delivering datagrams (packets) from the source host to the destination host solely based on its address.

E-MAIL
Electronic mail, or e-mail, allows computer users locally and worldwide to exchange messages. Each user of e-mail has a mailbox address to which messages are sent. Messages sent through e-mail can arrive within a matter of seconds.

Pop3 :
The Post Office Protocol version 3 (POP3) is a protocol used by local e-mail clients to retrieve e-mail from a remote server.

SMTP :
Simple Mail Transfer Protocol (SMTP) is a protocol used by local e-mail clients to send
e-mail from a remote server.

IMAP :
The Internet Message Access Protocol or IMAP is a protocol used by local e-mail clients to retrieve e-mail from a remote server.

TELNET
Telnet is a program that allows you to log into computers on the Internet and use online databases, library catalogs, chat services, and more.

FTP
FTP stands for File Transfer Protocol. This is both a program and the method used to transfer files between computers. Anonymous FTP is an option that allows users to transfer files from thousands of host computers on the Internet to their personal computer account.