system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: The difference between 32 bit and 64 bit computer programs.

I always see this and I never really know what it is. Does one run faster due to using more memory or something?
gpt
So the difference is really hardware, and a 64 bit program is one that is made to run on a 64 bit CPU.

Think of the CPUs as having doors that stuff can go through (data, program instructions.) The 32 bit CPU has 32 doors, the 64 bit, 64. So that's why software written for a 32 bit processor (or 16, or 8) can run on a 64 bit processor, some of the "doors" are just not used.