9.1 OSI Model
9.1.3 The presentation layer
The Presentation Layer provides communication services by transparently converting the different data, video, sound, and graphic formats to and from a format suitable for transmission. This layer is also responsible for data compression, decompression, encryption and decryption.

Although, these can be specific protocols, they are usually built into existing application layer protocols.

Some of the Presentation Layer standards involved include:
Text: ASCII, EBCDIC
Graphics: TIFF, JPEG, GIF, PICT
Sound: MIDI, MPEG, Quick Time

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