The higher the resolution, the sharper the picture. At the same time it will also mean the more memory that will be required to store an image, both in the camera and on your computer. A camera's memory size will determine how many images you can store. If you anticipate downloading your images often, buying a camera with a large amount of memory isn't as important. However, if you plan to take multiple pictures before downloading them to your computer you may want to buy a camera with a lot of included or expandable memory or plan to buy an extra memory card.
Some digital cameras have a non-removable memory chip embedded within the camera for storing images.
However, most consumer cameras use an external memory card or even a floppy disk than can be removed when full. To increase this capacity or number of photos, you can buy additional external memory cards. This is the process that shrinks a photo's file size. Most cameras take photos as compressed JPEG files, which allows you to store more images on a memory card. Compression, or compressing images also makes it faster to save, download, email and when compressed photos are used on a Web site it decreases the amount of time it takes for a browser to load a Web page for viewing.