How is the intel dual core better than the intel 3??

There are a lot of dual core CPUs from intel. Better than the... pentium 3?

I'm going to go with "How is the Intel Core 2 Duo better than the Intel Pentium 3?"
Well, the Core 2 Duo processors have 2 separate 'cores' on one chip, which means they can do two things at once. They also work much more efficiently than the old pentium 3's, even though the clock speeds aren't -too- much higher. The clock speed isn't all that matters, as long as you can do more work in each clock cycle.

They also have a faster transfer rate for data to other parts of the computer (like the RAM), and have more memory on the processor itself (called cache), so it's much easier for them to do a lot of complex operations, splitting up the work between 2 cores, than it is for the pentium 3, which has to keep getting more operations because of the smaller cache, and perform them one at a time.

Newer processors also support newer technologies, which makes them more compatible with current software.