A memory card or flash memory card is a solid-state electronic flash memory data storage device used with digital cameras and other electronics. They offer high re-record-ability, power-free storage, small form factor, and rugged environmental specifications. They are like film. (Wikipedia.com)

So, how much memory do you need? There are 3 factors when determining which memory card to purchase.

1. The number of images you would like to store on your card.

   See the chart below to determine how many photographs may be stored with your selected camera and card.

2. The resolution of your camera
   A large megapixel camera will produce a large file size per photograph. For example, a 10mp camera will store a 10mp file per photograph at the best quality.
3. The price you are willing to pay.
   A 4GB Compact Flash Card will sell retail for about $75.00

The most common memory cards are the Compact Flash Card and the Secure Digital Card. Sony uses a specific card called a Memory Stick.