GIS stands for Geographic Information System, software that can analyse data that has a geographic component.
I cam across it a while back, when I was looking at alternatives to using Inkscape for garden deign, I even met a GIS developer at the GovCampCymru unconference 2022. I settled on QCAD and I really haven’t looked back since.
GIS cropped up again when I posted a Mastodon summary of my new CAD for Gardeners class, and someone said “why not GIS?”. The main reason is complexity. 2D CAD has a steep enough learning curve, and really, for garden design the core functionality is plant spacing & plant quantities. GIS looks amazing (not that I’ve read up on it) but is probably overkill.
However, it would be good for larger scale projects. I am thinking about large scale ecological restoration, and if you could have data on eg native plant distributions across a large area, that could feed into design decisions. Possibly some sort of Citizen Science and Citizen Gardener project?