Basic Digital Photography

Compared to analog photography, digital photography makes use of CCD sensors to capture the data rather than photographic film. This marks the basic difference between the two. The CCD sensor consists of millions of tiny sensors arranged close to each other in a grid pattern. Each sensor captures and encodes the light/ color falling on it. When you hear talk about mega pixels you can keep this CCD sensor in mind. They are talking about how fine a detail we are able to capture using the sensor in the camera. Of course, after a point, it doesn't matter, since the human eye is not usually able to pick up that fine a detail (usually after around 4-5 megapixels). Unless, you are planning to take a really big print of that on paper.