##SDP stands for Session Description Protocol.
SDP is information created via createOffer() and/or createAnswer(). SDP is used to provide a callee with information about caller and vice versa.
- describes multimedia sessions, which can contain audio, video, whiteboard, fax, modem, and other streams.
- Provides a general purpose, standard representation to describe various aspects of multimedia session such as media capabilities, transport addresses and related matadata in a transport manner
- Used for session announcement, session invitation and parameter negotiation
- Used in the context of Session Initiation Protocol, Real-time Transport Protocol, and Real-time Streaming Protocol applications.
To be honest, all you need to know about SDP is that this is information that a caller and a callee must exchange in order to let each other know who he or she is.