OSI Model

OSI Model

OSI stands for Open Systems Interconnect

In order for network communication to take place, there needs to be a set of standards and that is why the OSI model was developed.

The OSI model describes how information from software in one computer moves through a network to reach software in another computer.

It does this by breaking down the huge task of data communication into 7 different layers giving control of the data being sent from one layer to another.

These layers are numbered from 1 to 7 starting from the bottom.

These layers are -

1. Physical Layer

2. Data Link Layer

3. Network Layer

4. Transport Layer

5. Session Layer

6. Presentation Layer

7. Application Layer

How data flows in OSI model ?

One Computer->Application layer->Presentation layer->Session layer->Transport layer->Network layer->Data Link layer->Physical level then to Physical layer->Data Link layer->Network layer->Transport layer->Session layer->Presentation layer->Application layer->Another Computer

When two computer want to communicate, the data flows down the OSI model and when the data crosses over the internet media such as the internet, it flows back up the OSI model to its destination.