Difference between an x86 and and x64 operating system ?
x86 represents the architecture of the PC in the same way that PowerPC and SPARC are different. This originated from Intels 286,386,486...etc processors. x64 relates to the number of bits. Most PC's run 32-bit applications but now 64-bit are available but not many applications support it. If you are looking for a home machine you will want a x86, 32-bit system to give you maximum compatibility.
x86 is more compatible and reliable with most of the softwares supporting you. Performance is good too.