The focal point of a CCD camera does not contain photographic film but a chip. This chip transforms the image into an electric signal. This makes the CCD camera comparable to a web cam. A big plus of CCD images is that the information is stored digitally. This helps to diminish light pollution, a problem that you frequently encounter in classical photography. In addition, images can be edited and compiled to achieve even better results.
A second advantage is that the chips are very sensitive compared to photographic films. This way, you will also be able to gather the light of weaker stars and shutter time does not need to be that long. Last but not least, the CCD camera can be used for accurate and automatic tracking of objects.
Using a CCD camera takes a bit of exercise and some experience with astrophotography is desired. As it happens, you will need to do two ‘trial’ shots to correct the ‘real’ shot with: a dark current shot to map camera noise and a shot of a neutral light source to register faulty pixels with.
Which camera is best for what purpose? Spherical pictures: are best made with a single-lens reflex camera in combination with a piggyback or flip mirror system and a wedge telescope or field rotator, a tracking motor and if necessary a Barlow lens.
Planets: a webcam. A webcam is able to do hundreds of shots in rapid succession. Special software picks the sharpest pictures and compiles them to form one image.
Deep Sky: for far-off objects it is best to use a CCD camera. A CCD camera is always used in combination with a pc.