What's the different of x32 and x64?

hello im just curios of What's the different of x32 and x64 here in hake.me? or launching the dota 2? hmmn anyone? im not aware and im noob or i dont even know what's the different. is it on game? or something? sorry for the numb question. :)
Its the architecture of your CPU. 64-bit CPUs can switch into 32-bit mode where they can run 32-bit applications along side 64-bit ones. 32-bit CPUs, however, cannot run 64-bit instructions. If your CPU is 64-bit you should use the 64-bit version of hake.me as well as Dota 2 for the best performance. We fully support both architectures here at hake.me.