They are treated exactly like two separate CPUs. Any operating system that can use multiple CPUs can also use a processor with multiple internal cores, with no changes needed to the code.
64-bit
Most operating systems are designed for either 32-bit or 64bit CPU's.
Multicore
In simple terms, 32-bit operating systems can only be able to run on 32-bit CPUs and 32-bit apps, but a 64-bit operating system can be able to run both 32-bit and 64-bit CPUs and apps.
Porting is the process of modifiying the operating system code to make it run on new CPUs and system architectures. For example, if the operating system was originally written to run on x86 CPUs and was later modified to run on ARM processors.
In a multicore or multi-CPU system, processor affinity refers to what cores or CPUs a given process can run on. The application can be forced to prefer some cores or processors over others.
It is a form of computer software where most limitations are 32 bits long, thus making the most RAM you can have to be around 4 GB. Most CPUs these days can handle 64 bit OSs (operating systems), such as Windows Vista 64 bit edition, Windows 7 64 bit Edition, etc.
The main problem is that such computers are way too slow for today's operating systems and applications. Today, the problem isn't so much the clock rate, but the fact that the CPUs used much less efficient instructions and were not multicore like today. The companies could make more efficient computers than what was produced back then if they wanted to, and using that same clock rate. Plus the memory during that time period was very slow.
It is a form of computer software where most limitations are 32 bits long, thus making the most RAM you can have to be around 4 GB. Most CPUs these days can handle 64 bit OSs (operating systems), such as Windows Vista 64 bit edition, Windows 7 64 bit Edition, etc.
32-bit or 64-bit CPUs/processors or operating systems indicate the address size for memory. A 64-bit address obviously can allow the computer to allocate much more than a 32-bit one. Otherwise there's not much differences (except CPUs in which most 64-bit CPUs have execute-disable bits that help prevent unauthorized programs from running)
The newest CPUs and video systems generate the most heat.
Cluster computing or distributed computing.