(CF) card is a memory card used in small portable devices mostly DSLR (Digital Single-lens reflex) cameras. CF cards are durable, portable and fast. There is a range of cards based on speed and capacity. Card speed relates to the speed of writing data onto the card and read speed relates to how fast data transfers from the card onto the device. Card capacity relates to how many GB of memory it can store.
Although SD cards are very popular and commonly found in portable devices and cameras, some high end brand name DSLR Cameras prefer CF cards for high definition digital stills and video. CF cards are durable and a little bigger than SD cards so may be easier to handle and harder to loose. In terms of speed and quality one can find a perfect fit in both CF and SD category of cards.
There are two main types of CF cards. The difference is in size. Type I ( 3.3 mm-thick) and Type II (5 mm-thick). Type I will draw up to 70 mA electrical supply, while Type II devices may draw up to 500 mA.
Capacity and Speed
Today, on the market, there are CF cards with capacity ranging from 2GB up to 512GB. How much capacity you need depends on what you are using the Compact Flash card for. Be aware that higher capacity tends to cost more. The speed with which the data is transfered from the device onto the card and off the card to the device is very important if you are doing some serious photography. CF cards that have read and write speeds of 160MBs and 150MBs are perfect for professional photography. These cards can handle thousands of high resolution still images and process high definition videos at about 65MB per second.
Ultra CompactFlash (UltraCF) is optimized for high resolution burst photography of moving objects. UltraCF has a higher transfer rate than CF cards so it allows for faster data transfers so that the high definition image can save quickly and the camera can take another shot.
Also known as CompactFast, although it looks the same as any Compact Flash card, it is built differently and with speed in mind. It is based on the Serial ATA (SATA) interface rather than the Parallel ATA/IDE (PATA) bus found in CompactFlash Cards. It supports much higher maximum transfer rate speeds so it is no wonder the early adopters were in the gaming industry. CFast is almost the same size as CompactFlash card, however CFast cards have 24 pin connectors where CompactFlash cards 50, so to use a CFast card in the CompactFlash card slot you would need to have an adapter.