OSI Network Model

Layer description

The application layer provides the corresponding interface for users to use the network connection function.
The presentation layer completes data formatting
The Session Layer controls the communication links between two hosts (open, operate, and close)
The transport layer provides data transmission services (reliable or unreliable)
The network layer provides a addressing/addressing mechanism between two hosts and is responsible for packet routing.
The data link layer controls the physical communication links between two hosts. It is also responsible for shaping data for transmission over physical media.
Physical media is responsible for transmitting data in the form of a series of electronic signals.

Figure 1-1 OSI Network Model