Heisenberg Picture
Definition
Quantum mechanics with the operators moving instead of the states — mathematically equal to Schrödinger's view, and preferred in field theory.
Technical definition
States stay fixed while operators evolve: dÂ/dt = (i/ℏ)[Ĥ,Â] + ∂Â/∂t. It is unitarily equivalent to the Schrödinger picture.
Example
Quantum field theory calculations usually run in the Heisenberg (or interaction) picture — the fields themselves become the evolving operators.
Common confusion
The Heisenberg picture is not the uncertainty principle — same Heisenberg, different idea. One is a formulation choice; the other is a physical limit on measurement.