What is the difference between the Intel x86 Atom and Atom_64 system images?

Question

I am using the Android SDK Manager to install the system image for the Android M Preview. However, I noticed that there are two separate images for the x86 platform.

Answer 1

FYI: In the official Android Studio documentation it says that "x86 system images run the fastest in the emulator."

I haven't tried the 64bit, so I can't really comment on that. Maybe someone else can.