Communication has the same age as life on Earth. Unicellular organism have found that if they receive and interpret chemicals signals from the environment, in some cases they can gain some advantages in front of the “competition”, advantage that can delineate success of the failure. From the message receiving, was then passed to their release as warning signals against enemy, or calling for dinner.

Multicellular formation of the organism has been possible dues to communication between cells, after all each man is composed of many cells. Between animals (of any kind they may be), communication has several roles: the delimitation of territory food, pack meeting, guidance to better places of food, maintain the group hierarchy, calling partners. The communication facilitates the activities which are meant to satisfy the preservation instinct of the individual or species.

To human, communication has reached a new level; moving from primary requirements, reaching the sharing states (feelings, physical stimulation), of the actions ( strategy, history ) and of ideas. The technical way through which communication takes place, evolved too; from the African drumming , or the Indian smoking clouds to the writing, telegraph, telephone, radio, television, internet.

The Sociology dictionary defines communication as a process of issuing a message and submit it in an encrypted manner, to a recipient for the reception with the help of a channel. The Psychology dictionary defines communication as: a relationship between individuals involving the intentional transmission but not to affect the receiver but with retroactive effect. The internet communication may have as interlocutors two people ( one man and one computer) or two computers.

Once with the development of the internet structure (quantitative and qualitative) the available services have multiplied and diversified too. Initially on the internet you could only send emails, talk in real time and send files from one computer to another. After that they were created some services for publishing the information, index services and searching services. Later, occurred a service of publishing the information (text and graphics), World Wide Web, which has become so popular that today many users consider it as a synonymous with the internet.

For understanding the internet, we must talk a bit about computer networks. In items of communication, we are interested especially in the physical environments trough which communication is performing and the rules for transmitting the information between computers.
-  Local network, LAN ( Local Area Network ), consisted by closely spaced computers, they are relatively small, usually a department, company , etc.
- Metropolitan networks, MAN ( Metropolitan Area Network), which they are covering a town or a part of it, for example a university with more buildings lying apart.
- Wan networks, WAN ( Wide Area Network ), which they are covering large areas as a country, a state.

Typically, the speed of communication between two computers (both - the theoretical and practical), decreases when the distance between them increase, and also the security and stability. We must make the distinction between theoretical speed and the real speed of communication which in some cases, can be significantly lower, depending on the network load or of the delays that can appear.
From case to case, communication can be:
-   Simplex – one of the computers only transmits, and the other only receives.
-  Duplex or full duplex – the computers transmit and receive simultaneously
- Half-duplex – one computer issues and one is receiving and after a time the roles are reversed.