What's the difference between MSK constellation and GMSK constellation?

There are four points on MSK's constellation diagram with a phase difference of 90 degrees.

Compared with MSK constellation, GMSK constellation has two points next to each point-* *12, which is caused by intersymbol interference caused by the signal passing through Gaussian low-pass filter first.

To put it bluntly, GMSK is to increase intersymbol interference to improve the transmission spectrum.