I want to get a 3D printer, what is the difference between printers of various materials?

I want to get a 3D printer, and usually print some parts with high structural strength requirements. I found on the Internet that nylon and reinforced resin have relatively high strength. I would like to ask what is the difference between printers of various materials? How should I choose? Can I save one by myself? Is it possible for metal 3D printers to be used by individuals?