The port is where nodes receive and send data. Data enters nodes through input ports, either as signals, or parameters, then signals (and signals only) leave via output ports.
Ports on a node
Ports have data types associated with them, which helps determining whether a parameter or a connected port is compatible. Connecting incompatible ports may lead to unexpected behavior (bugs).
Port's data type on the prototype tab
Port's data type on the instance tab
Data types in CRANQ must be compatible with JSON, including strings (text), numbers, boolean (true / false), null (special value), arrays (lists), and dictionaries (records).