An electric grinder is an electrically powered sanding tool, and there are all sorts of different varieties. Nowadays, with the popularity of lithium-ion tools, cordless sanding tools are replacing wired abrasives in a big way.

Angle grinders
A universal power tool, the most used tool for sanding or cutting, with more safety hazards, do not use it to cut wood, or you will end up in a very bad situation.

Electric sanders
There are round discs and square discs. Also known as a sander, woodworkers use a lot of them.

Belt sanders
Uses wide and long sanding belts for sanding large materials.

Sanding disc machine
A rotating one, fixed to the table or hand-held, in various sizes.

Sander
Also known as a bench grinder, suitable for sharpening tools, drills etc.

Belt sander
Also known as a tank sander.

Grinders
A fine grade grinding machine, expensive, factory use, for sharpening knives, magic edges, e.g. various drills, machine tools, turning tools, etc.

Wall sanders
Sanding putty, wall levelling

Floor sanders
Sanding of flat floors, concrete floors, etc.