OSI Model

Presentation Layer

The presentation layer serves as the data translator for the network. This layer on the sending computer translates the data sent by the application layer into a common format. At the receiving computer, the presentation layer translates the common format to a format known to the application layer.

The presentation layer provides the following functions:

Character-code translation, such as from ASCII to EBCDIC.
Data conversion, such as bit order reversal, CR to CR/LF, and integer to floating point.
Data compression, which reduces the number of bits that need to be transmitted.
Data encryption and decryption, which secures data for transmission across a potentially insecure network. One use of encryption is for transmission of a password to a receiving computer.