how wide are 32 and 64 bit architecture buses?

Question

I was reading my Systems Programming book and got to a chapter about Hardware organisation of Systems. This was first time me reading about Hardware organisation of Systems so I got really interested and try to understand as much as possible. This is the first time I understood the difference between 32 bit and 64 bit architectures. But Im still confused. As I understood Buses are the paralel lines that move information in computer for example from cpu to I/O bridge. But I didn't really get does each line in bus carry one bit or a whole byte? In other words does 32 bit system bus have 32 lines or it has just 4 parallel lines which transfer a single byte? or does 64 bit system have 64 parallel lins or 8 parallel lines? I tried to find the answer but couldn't find it.

does transfering 1 single 32 bit information look like this?

---0--->          or like this  --01011100-->
---1--->                        --10000100-->
   .                            --11010111-->
   .                            --01011101-->
   32 times
   .
   .
---1--->
---1--->

P.S. I am a bit wasting time at looking in such a detail, but I really got interested.

Answer 1

If you have 32-bit parallel bus it indeed transfers 32 bits of data simultaneously (synchronously with clock). However, bus width is in general independent of whether system it is 32 or 64 bit system