Sockets define what kind of message the node receives and sends out.
If you know what data will "come in," choose the group and the type of socket from the list (1). In this example, this is the Common group and AnyData type.
Usually, a socket group corresponds to a specific Aitheon service.
If you are not a developer, you don't need to know data types and sockets. You may outline the automation on the graph table just by using the AnyData socket of the Common group.
During the initial deployment, this socket will automatically transform to a socket of the corresponding type:
In this example, outputAnyData (this is the name, not a type of socket) with the socket of AnyData type will transform into a socket of Message type - due to the connected incomingMessage output socket.
So basically, AnyData socket allows you to build some business logic connecting nodes and sub-graphs without paying attention to technical details. If you describe your needs and use cases in a request or a provisional node properly, a developer will set up appropriate sockets and other settings for you.
If you need to connect not corresponding sockets, you may create a Mapping node.