A console game was compiled for one specific processor and piece of hardware. For it to run on a PC, someone has to bridge that gap — and there are four ways to do it, with very different consequences for performance, for mods and for what you need to have on hand.
None of them does away with the game: the code and the art belong to whoever made it, and the projects distribute only their own work. That is why every port asks for your copy — and why PCPort never points at game files.
Decompilation and native ports
In a decompilation, people rebuild by hand a C source that, once compiled, produces a binary identical to the original, byte for byte. It takes years. When it is done, the game no longer depends on the console: it can be built for Windows, Linux or Mac, given a new renderer, an uncapped framerate and mod support.
The result is a native port — the game becomes a real PC program with nothing emulated in between. It is the approach that gets the most out of modest hardware.
Static recompilation
In a recompilation, a tool reads the original machine code and translates it automatically into C or C++, which is then compiled for the PC. Tools such as N64Recomp and ReXGlue made this viable for whole libraries, which is why most new ports arrive this way.
It is much faster than decompiling by hand, and the game runs natively too. The difference is that the generated code is not meant to be read: fixing and modding it is harder than in a decompilation.
Translation layer
Here the original executable runs directly on your processor, and only the calls to the console's system and graphics hardware are converted while the game runs. It sits between a native port and an emulator: lighter than emulating everything, less predictable than a hand-made port.
In the catalog
Emulator
An emulator recreates the whole console in software and runs the original game unmodified. It asks much more of the machine, but it covers the console's entire library at once — the way in when the game you want has no port yet.
Which one to pick
If the game has a native port or a recompilation, start there: it usually runs better, with widescreen and a free framerate, and every page’s install guide says exactly which copy of the game the project accepts. The emulator is for when no port exists — or for playing several games from the same console.