For millions of potential camera shoppers, choosing the smallest, lightest camera is most important.
Megapixels are important and a camera must have enough of them to provide adequate image information for the size print being produced so that there is less noise and better clarity in the resulting image.
The sensor can be either CCD (charge-coupled device) or CMOS (complementary metal oxide semiconductor). CCD is the more mature technology and produces images with less noise.
An important aspect of the CCD is the actual size of the sensor. Larger sensors provide higher resolution and less noise. Understanding how the size of the CCD sensor influences the quality of images and knowing what size sensor is adequate requires a bit more study.
A final consideration regarding the sensor in a digital camera is the availability of 1 CCD and 3 CCD models. As one might suspect more is often better. A camera with 1 CCD picks up image and color information through a single sensor. A model with 3 CCD has a sensor that picks up each of the different colors (Red, Green, and Blue) resulting in superior color reproduction.
Certainly the selection of a CCD sensor over a CMOS sensor, a larger sensor, or more sensors is not required in order to own a high quality digital camera capable of producing very good images.