The light detector or image sensor is known as charged couple device (CCD) and it's made up of individual light sensitive picture elements typically referred to as pixels. Digital cameras are often measured in megapixels or millions of pixels. A camera which has a 3000 x 2000 array of pixels within the image sensor would contain 6,000,000 pixels and would be referred to as a 6 megapixel camera. As soon as the light hits the CCD it breaks it up in to the millions of pixels and measures the amount of light and color to come up with a number for each pixel. Your digital picture is actually a long string of numbers that's stored on a file in memory. The LCD screen on the back of the camera shows you the picture which the CCD is capturing.
Digital photographs have to be compressed or the file size is enormous and take up way too much memory. The most frequent compressed format is JPG which stands for Joint Photographic Experts Group. The larger the amount of photo info is kept the better the image quality and the bigger the file. The more compressed the photo is, the lower the quality and the smaller the file size. The smaller file size makes for shorter load times plus you are able to store more photos in memory. You do sacrifice quality however.
The fact that digital images are stored digitally ensures they are incredibly easier to store, share and manipulate. Whenever you open a photo inside an editor such as Photoshop, you are able to customize the excellence of the photo by clicking on a setting. When you do this it changes the numbers which the pixels are storing to create the effects. For example, if you need to make the picture 10% brighter, the image editor would change the pixel numbers by 10 percent to show increased light or brightness. Some digital cameras have built-in effects and you may make a photographic effect in the camera immediately after you take the picture. Something you simply can't do with film cameras.