Binding is a read-only TIdSocketHandle property that represents the socket handle used to establish the network-level connection to a remote computer system for the socket-based IOHandler. 

Binding provides methods used to create, open, close, read, write, and maintain options used on the socket descriptor. 

Use Open to ensure that the Binding contains a valid socket handle for the IOHandler connection. 

Use Close to ensure that Binding is disconnected. 

Binding is freed in the destructor for the object instance.

TIdSocketHandle 

TIdIOHandlerSocket.Open 

TIdIOHandlerSocket.Close 

TIdIOHandlerSocket.Destroy