Fundamentally - it's different only in length of memory address. So on 32bit OS we can use only 2^32 memory address = 4Gb of RAM. But it different entails update all system files. So it's look the same, but it really different OS.
When using a 64-bit OS and applications, two main speed advantages for applications comes from a reduced need to swap memory into disk and the ability to pass function arguments in registers instead of stack memory.
Genraly 32 bit system can contain i mean use 3 gb (3.9) of RAM memory when 64 bit can use alot mote when i say alot more i mean 100+ gb and yes 64 bit can handle more programs aka Apps 64bit is more usable in gaming indystry computer sience and enginering too, rendring, servers for some platform smillar like VPS (virtual private server)