Stages can do EOR and EOC 
A modulation source that can be envelope-like, sequencer-like, LFO-like, or fader-like. It can also process CVs: sample+hold, delay, slew, trigger-to-gate, sequential switch. And you can separate it into multiple independent parts by patching it.
So it can be one 6-stage sequencer, or an ADSR and two simple LFOs, or 6 decay envelopes, or a trapezoid LFO and a delayed copy of the same LFO, or 3 LFOs and a 3-step sequential switch that selects between them, or an ADSR where the sustain stage is an LFO… etc.