This segment from Bitwig's official modular tutorial walks through three phase-processing modules in The Grid: Phase Reverse, Phase Shift, and Phase Reset. Each one changes how step sequencers relate to each other in time, without touching the underlying clock or step count.
Phase Reverse flips the playback direction so two sequencers with identical data are never on the same step simultaneously. Phase Shift offsets one sequencer by a percentage of the cycle, so at 50% they are always half a phase apart, and that relationship holds even when the two sequencers have different step lengths.
Phase Reset ties the restart point of all sequencers to an incoming signal, such as a new MIDI note. The sequencers keep running in sync with the master clock, but where they start in their cycle shifts every time a note triggers. This makes phase a flexible relative reference rather than a fixed position in time.