With the variety of digital cameras on the market today, they all seem to use different media and come in all types of speed variations, we have put a small list of the main digital media that's available today and list the small differences between them.

We have also have a simple graph to explain how many images you will fit on your  file / memory card , as well as explaining what the speed difference's between different manufactures.
 

	Compact Flash
	Compact Flash or CF cards are popular in devices that can spare a bit more space inside, as despite their name, Compact Flash cards are among the largest cards in terms of physical size. Compact Flash cards offer a significant range of speeds and capacities, up to 4Gb and 10Mb/second – but more about speeds and capacities later. Important to note is that Compact Flash cards come as type I cards and type II. Type II cards typically allow higher storage capacities but are also physically a much thicker card. When buying a CF card, it is therefore important that you check which type of CF card your device supports.
	MicroDrives
	IBM developed a miniature tape drive called the MicroDrive with the physical dimensions of a Compact Flash type II card. MicroDrives are comparatively rare and if your device supports the format it should say so explicitly in your user manual. MicroDrives come in 340Mb / 512Mb / 1 Gig / 2.2Gig capacities.
Memory Stick MS Duo	Memory Sticks
	Memory Sticks (MS) were developed by Sony, to provide flexible storage for many of their products. Memory sticks are found in a variety of devices and offer great versatility – but unfortunately a lot of confusion as well as Memory Sticks come in a number of different formats. Physically speaking, there is the standard Memory Stick and the Memory Stick Duo, which is shorter and thinner. There are also differences in the ‘controller’ software on various Memory Sticks. Again, there is the standard Memory Stick and there is the Memory Stick Pro. The same goes for the Memory Stick Duo; it too comes as a standard MS Duo or an MS Duo Pro (sometimes also called Pro Duo). When buying an MS Duo Pro, you will oftend find that it comes with an adapter that will let you use the MS Duo Pro as an MS Pro – the controller software is the same.
	Olympus XD
	xD (Picture) card slots are found in Fuji and Olympus cameras, as the cards were developed by these companies. xD cards are often sold under license and therefore you may sometimes find a different brand on the packaging, but a Fuji or Olympus branded card inside. xD cards have a distinctive, shield style design and are roughly the size of your thumb. Storage capacity can be anything from 8Mb to 512Mb.
	SD Card (Secure Digital)
	By physical dimensions these are the smallest of the memory cards and are therefore commonly used in ultra-compact products. The only difference between Secure Digital cards and MultiMedia Cards is that Secure Digital cards have a write-protect switch for added data security.

* Actual results will depend on the digital camera model, resolution and compression mode setting.

Memory Card Speed  

A common question is whether or not a camera or other device will support a certain speed, for instance a 30X card. The answer to this is that modern cameras have the ability to support far higher speeds than any card you might be able to purchase today. Therefore, if speed is of importance, you can safely buy the fastest card you wish to afford.

Card speed is often stated in ‘Times’ speed (8X, 20X etc.) and sometimes, more specifically, in Megabyte per second - reflecting the card’s per-second ability to have data transferred from or to it: