GBand is a resonant band-pass filter.
A typical band-pass filter is configured by selecting a central frequency "node" and adjusting the Q (width) of the band surrounding the node. GBand operates in a much more intuitive way. It is actually composed of a low-cut and a high-cut filter operating in series. In GVST terms, this plug-in is identical to having a GLow and GHi running one after the other.