These days, things have become streamlined and easier overall, thanks to a program known as RetroArch. To play games that appeared on different consoles, you had to install and configure multiple programs - one for each console you wished to emulate. In the past, emulation was, more often than not, something of a juggling act.
In addition to RetroArch, which covers a large range of retro consoles, there are also several stand-alone emulators that can fake more recent hardware - even the Nintendo Switch. Thankfully, there’s one go-to emulator for most platforms.
Because emulators often meddle in a legal gray area, it can be hard to find emulators that run classic games consistently. The best emulators allow you to replay classic games from systems like the Super Nintendo and PlayStation 2 on modern hardware - and usually with some enhancements to boot.