Heisenberg picture

Short definition from Wiktionary

Noun

1. 1
   A formulation of quantum mechanics in which the operators (observables and others) incorporate a dependency on time, but the state vectors are time-independent, an arbitrary fixed basis rigidly underlying the theory. It stands in contrast to the Schrödinger picture in which the operators are constant, and further serves to define a third, hybrid picture, the interaction picture.