Convolution reverb uses impulse responses (IRs) recorded in real spaces — a cathedral, studio room, or legendary hardware unit. The convolution engine applies the IR's acoustic signature to dry audio, making it sound like it was recorded in that space. Convolution is also used for room correction: the inverse of a room's impulse response cancels its acoustic problems.
Convolution is computationally expensive but produces the most realistic reverb and the most precise correction. Found in: Altiverb (convolution reverb), Sonarworks SoundID (room correction), and guitar cabinet IR loaders.