Digital cameras provide image quality equivalent to or better than what you can achieve with a traditional camera and scanner. However, a digital camera is considerably more expensive than a conventional camera or general purpose scanner. Someone who shoots photos for a living likely wants a digital camera that provides all the flexibility and control of a traditional camera. This depends on how many individual image sensors are present in the array. When you do the multiplication a camera with resolution of 1024x768 has 786,432 sensors and produces the same number of pixels.
More pixels mean better resolution and sharper images.
Many cameras offer megapixel resolution which sounds like a Japanese movie monster, but it's actually one million pixels. How many pixels you want is influenced by the image quality you require and the size of photos you want to print. For instance, to take basic pics to post online, a 640x480 camera will suffice. Those of you with deeper pockets and a penchant for photography can go the extra mile and buy two-megapixel models. Professional cameras now support three and even four megapixels.