A single imaging-chip based camera has that imaging chip processing all three primary colors (Red Green Blue).

A 3-imaging chip based camera has one chip per primary color working together.

I intentionally did not specify CCD/3CCD vs CMOS/3CMOS. There are some camcorders available that use CCD technology and some that use CMOS technology.

In each case, there's a lot to read that we do not have space to re-hash here...

http://en.wikipedia.org/wiki/Image_sensor

http://en.wikipedia.org/wiki/Charge-coupled_device

http://en.wikipedia.org/wiki/3CCD

http://en.wikipedia.org/wiki/CMOS

In the consumer camcorder space, I *think* Panasonic has the line on -chip camcorders, but they are at the higher end of the line. In the "prosumer" space (usually Sony), their HDR-FX7 and HDR-FX1000 are great for their large 3-chip imaging systems combined with the large lenses.

Some say CMOS is not as good as CCD...