What is the difference between x86 and x64

x86 is for a 32-bit OS, and x64 is for a 64-bit OS

x86 is a 32 bit instruction set, x86_64 is a 64 bit instruction set... the difference is simple architecture. in case of windows os you better use the x86/32bit version for compatibility issues. in case of Linux you will not be able to use a 64 bit s/w if the os does not have the long mode flag.

Whatever I recommend if you have a windows 7 32 bit OS then go for 32bit or x86 binaries and as for Ubuntu 12.04 use command uname -a or grep lm /proc/cpuinfo (grep lm /proc/cpuinfo does not return value for 32 bit as 32 bit os does not has the cpuinfo flag) to know the architecture OS your OS then use the binaries according to your OS.

** Note. Remember you can always install 64 bit os in 32 bit system as long as it supports enhanced 64 bit.. 64 bit os works better some times for multi purpose work and also supports more ram than 32bits. also you can install 32bit s/w in 64 bit os..

** OS = Operating system.

The difference is that Java binaries compiled as x86 (32-bit) or x64 (64-bit) applications respectively.

On a 64-bit Windows you can use either version, since x86 will run in WOW64 mode. On a 32-bit Windows you should use only x86 obviously.

For a Linux you should select appropriate type x86 for 32-bit OS, and x64 for 64-bit OS.