64 bit or 32 bit?

I purchased an iMac in 2008, and was going to download some software for it. I had to choose whether it was a 64 or 32 bit Intel; how can I find that out? And what exactly does that mean anyway?

Your machine has a Core 2 Duo CPU, which is 64-bit. You are most likely running 10.5 (Leopard), unless you've upgraded it to 10.6 (Snow Leopard). Either way, you're able to run 64-bit software.

http://www.mac-forums.com/forums/os...4-bit-snow-leopard-what-64-bit-means-you.html

If it is a core 2 duo intel chip then it will run 64 bit apps.

Even if you are not running Snow leopard, versions of Mac OSX have been able to run 64 bit apps since OSX 10.4 Tiger. So even if your OS kernal is running in 32 bit, it can still run 64 bit apps.

That said, which one you download will not be critical, the OS will be able to run the 32 bit or the 64 bit version on that iMac