When the networks first came into being, computers could typically comunicate only with computers from the same manufacture. Now take a look at the sample below ;)
The Companies ran either a complete DECnet solution for an IBM solution but not together
So, In the late 1970s(CMIIW), the OSI(Open Systems Interconnection) Model was created by the International Organization for Standardization interoperable network devices. It’s look like a world peace right? :)) It will probably never happen completely, but I think it’s still a great goal :P
The OSI Model is the primary architectural model for networks. It describes how data and network information are communicated from application on the computer, through the network media, to an application on another computer. The OSI reference model breaks this approach into layers.
So, what the hell is reference model? It’s look like a conceptual blueprint of how communications should take place. It addresses all the processes requied for effective communication and divides these processes into logical groupings called layers. When a communication system is designed in this manner, it’s known as layered architecture.