The main difference is in
1) the post processing. resin is messy and requires washing in isopropyl alcohol followed by exposure to an ultraviolet illuminator - the resin is also quite toxic and gloves should be worn at all times wheile dealing with uncured resin.
FDM filament occasionally needs a little sanding :-)

2) the way the files are sliced. resin files are converted in to stacks of flat 2d black and white images (NOT gcode) - 1 image for each layer.
For fdm the models are converted into a series of instructions called g-code, that tell the printer how and when to move the print head and/or print bed and extrude filament.

Fdm is the easier and cleaner and safer method.
While resin is the one with more solid results and much higher resolution prints.

Both can produce prints in many colours and material types.

Resin - while prices have been dropping - is still at least 2x the cost for materials

It is very much: get the right tool for the intended job.