"The Presentation Layer (layer 6)
At the Presentation layer of the OSI model, the data being transmitted is translated. The layer is responsible for translating data between the formats which the network requires and the formats which the computer is anticipating. The presentation layer translates the formats of each computer to a common transfer format which can be interpreted by each computer.

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"The Presentation Layer (layer 6)
At the Presentation layer of the OSI model, the data being transmitted is translated. The layer is responsible for translating data between the formats which the network requires and the formats which the computer is anticipating. The presentation layer translates the formats of each computer to a common transfer format which can be interpreted by each computer.

The functions performed at the Presentation layer of the OSI are:

Protocol conversion
Data translation.
Data encryption and decryption
Data compression
Character set conversion
Interpretation of graphics commands.
Data is translated at the Presentation layer when it is transmitted from the sender to the receiver. The application of the sender moves the data to the Presentation layer. The Presentation layer translates the data to a common format which can be read by both computers. When the data is received, the Presentation layer translates the data to a format which the application can read.

Gateway services also function at the Presentation layer. A gateway can be defined as a connection point between networks which run different systems and applications. Gateways are typically deployed through software. An example is Gateway Services for NetWare (GSNW).

Common gateways include:

Gateways which cross platforms and file systems
Systems Network Architecture (SNA) gateways enable PCs to communicate with mainframe computers.
E-mail gateways enable data to be transmitted between different e-mail applications running the same protocol. "