Coupling and Cohesion.
The degree of coupling refers to the strength of a connection between two routines. Coupling is a complement to cohesion. Cohesion describes how strongly the internal contents of a routine are related to each other. Coupling describes how strongly a routine is related to other routines. The goal is to create routines with internal integrity (stong cohesion) and small, direct, visible, and flexible relations to other routines (loose coupling).
Steve McConnell, Code Complete (1993).