Take the tour ×  I know there are 32/64 bit OS in the market.
Q1-> But what does this bit mean actually ? Q2-> What is the
lowest bit OS and highest bit OS ?  share|improve this question
I think it has to do with the size of an instruction in the cpu,
but off top of my head I don't remember too well, look up at
wikipedia. –  Cupcake Jul 2 '11 at 10:09 add comment  migrated
from stackoverflow.com Jul 2 '11 at 11:15  This question came
from our site for professional and enthusiast programmers.  2
Answers  up vote 6 down vote accepted  This means the number of
bits used for addressing in memory.  On a 32bit system an
address has 32bits. A bit is a 0 or 1, so if you have 32 bit you
can have 2^32 possible combinations which is about 4 Billion. It
also means that you cannot have more than 4 Billion addresses in
memory. --> since every address usually links to one byte, a
maximum of 4 Billion bytes can be addressed with a 32 bit
system. Hence the 4 GB memory limit for 32 bit operating systems
(Although Physical Addr