I am looking into buying some 44 Magnum bullets. I see a lot of plated bullets. Exactly what is the difference between jacketed and plated. Jim

Plated bullets are lead cast or swaged bullets coated with a copper or other alloy to keep you from getting lead poisoning and for less barrel fouling.
Jacketed bullets are a 2 pc construction. They have a lead core with a copper jacket swaged around it.

Plated bullets, e.g. Ranier, Berry, etc., provide inexpensive plinking and target loads when lead is not available or appropriate. One of the indoor ranges I use this time of year prohibits lead, so I sometimes have used a plated bullet.

None of my handguns proved to be very fond of these, so I have mostly switched to shooting Hornady XTP's for indoor shooting. Use lead for the outside range.

Plated bullets are not designed for effective hunting or self-defense use.

BTW, welcome to AR, Jim.