Quick answer
Sand (abrasive) blasting is the general pressure/media process; grit blasting emphasises angular media for profile; shot blasting usually means turbine machines throwing spherical metallic shot for automated cleaning and peening.
Sand / abrasive blasting
In everyday speech, “sand blasting” often means any compressed-air abrasive blast with a pot, hose and nozzle — even when the media is garnet or slag rather than sand.
Portable pots, cabinets and rooms all fall under this family when air pressure drives the media.
Grit blasting
Grit blasting highlights angular abrasives that cut and profile steel for coating adhesion. Equipment may look similar to sand blast pots and cabinets; the difference is media and finish intent.
Shot blasting
Shot blasting commonly refers to wheel/turbine machines that fling metallic shot at parts on tables, hangers, barrels or conveyors — high throughput for castings and fabrications.
Portable “shot” pots also exist, but if you need automated foundry-style cleaning, look at turbine shot blast machines rather than a hand nozzle alone.