system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: x64 means 64-bit but x86 means 32-bit?
gpt
Back in the 70s Intel released a CPU called the 8086. They followed that up with the 80186, then the 286, 386 and 486. Each one used an instruction set built on the previous one, which meant for the most part software written for one would work on newer ones.

This family of CPUs and the instruction set the used became known as x86.

Eventually they made the jump to 64 bit (it was actually AMD which first did this) which became known as x86-64. Then people just shortened that to x64.