Definitions for "Memory Cards"
A memory chip is similar to a small floppy disk. This type of chip primarily stores information, access control, or a value that can be "spent".
These are small memory modules that can be inserted into the camera to hold images. When the card is full it can be removed and another card inserted. The memory on these cards is non-volatile-m that is, they don't lose their images when they are removed from the camera. The image can be later downloaded from the card, and when the images are erased from the card it is ready to be reused. These cards are good for a lot of reuses- one manufacturer just warranted their cards for a minimum of 1,000,000 images.
Most digital cameras use removable memory cards to store images. They are essentially "digital film" and the data stored on the cards can be transferred and erased. The cards are available in a range of storage capacities, measured in megabytes. There are various formats including CompactFlash, Memory Stick, SecureDigital, SmartMedia, and xD Picture Cards.