TIdContext = class(TIdTask);

TIdContext is a TIdTask descendant that implements a session context representing client connections to a multi-threaded TCP server. 

TIdContext instances are used in TIdTCPServer, and descendant classes, in the Contexts property. Session contexts are created by the listener thread(s) for the server when a connection request is accepted by the listener thread. 

TIdContext maintains an association between the peer connection for the session, the thread or fiber used to execute the tasks for the client session, and the list of TIdContext instances active in the server. 

TIdContext also provides event handlers that allow execution of the task for the client connection using the OnConnect, OnExecute, and OnDisconnect event handlers in the TIdTCPServer instance.