This is independent from Toby's request for a portamento. This is a "whole instrument" pitch-bend. This means that all active notes (of this instrument) are adjusted by a specified amount of cents. This allows for some cool things not available in portamento:
Can use a controller to adjust the pitch. This is synonymous with the MIDI Pitch CC.
We can add an envelope to the Instrument ENVs for Pitch.
We can attach a controller (for example an LFO) to the pitch-bend for a cool vibrato effect.
The pitch can be adjusted in all fashions in the middle of a note. Portamento is restricted to a single source->destination pair.
Of course, portamento has the benefit of adjusting simultaneous notes differently.