what does 32 bit or 16 bit means when it is referred in terms of a
compiler? For example what does 2 bit stand for when we state a
complier as 32 bit.
The number of bits in a compiler refers to the basic number of bits
that can be manipulated as a unit on the target machine (processor). A
32-bit machine has a word size of 32 bits and presumably a bus width
of that many bits. A 64-bit machine has twice that width. Compilers
can be native or cross-platform, for example, a compiler might be
capable of running on an x86 machine but targeting another processor
like the M68000 (16-bit) or Z180 (8-bit) processors.
It is also possible to run a 64-bit OS and a 64-bit version of a
compiler and create 32-bit or even 16 or 8 bit executables.
Apple's Xcode can produce "Universal" binaries that can run on their
32-bit Intel machines and also on the PPC machines which had 32 and 64
bit modes.