External card readers are handy devices that allow you to read and write memory cards such as SD, microSD and CompactFlash cards on your computer. They are compact and easily portable, usually connect to the computer via a USB cable and offer fast data transfer. Examples may include multi-card readers that support multiple card types, or readers designed for individual card types, which may have additional features such as built-in security or high transfer speeds. External card readers are particularly suitable for photographers, videographers and others who need an efficient and easy way to transfer files from memory cards to a computer.