Each SSL connection involves one session at a time, but that session may be used on many connections between those entities, simultaneously or sequentially. The session used on a connection may also be replaced by a different session. Sessions are created, or rejoined, as part of the SSL handshaking protocol. Sessions may be invalidated due to policies affecting security or resource usage. Session management policies are typically used to tune performance.
Sessions are between a particular client and a particular server.
The identity of the peer may have been established as part of session setup. Peers are identified by X.509 certificate chains. Cipher Suite Name. Cipher suites describe the kind of cryptographic protection that's used by connections in a particular session. All connections in a session are between the same two hosts.