Fields are replicated with discrete p-forms, which
Grad, curl, and div are replaced with discrete exterior derivatives, which
Material or metric is included in discrete Hodge star, which
For details, see our presentation.
The main focus is on time-integration of wave equations. With DEC, the wave equations are expressed in a way that the "discrete energy" conserves during the time-integration. See the Online time integrator, where you can play with two-dimensional wave in real time.