Fedora 7: lib64 directories

[Shams]

Hi,

I have installed Fedora 7 on a 64-bit cpu.
I noticed that Fedora has both /usr/lib and /usr/lib64.

1. Is this only on Fedora or standard across many Linux distros?

2. Technically why is this needed, can it be just  solved with having all 
the 64-bit libs in /usr/lib?

3. Also if I have a 64-bit cpu that is not capable of supporting IA32 will 
then only /usr/lib exist?

4. Also does this mean that a lot of installed packages are still 32-bit?

Thanks
Shams