Data coupling

When a module accesses another module, inputs and outputs are exchanged by simple data parameters (not control parameters, common data structures, or external variables).

Folding tag coupling

A set of modules that pass record information through a parameter table is called tag coupling. The record is a substructure of a data structure, not a simple variable. You're actually passing in the address of this data structure;

Folding control coupling

Control coupling occurs when a module clearly controls the selection of another module by transmitting control information such as switches, flags, and names.