An SD card reader is a device used to read data from Secure Digital or SD memory cards. Memory cards are commonly found in portable electronic devices, such as digital cameras, phones and tablets.
Some laptop and desktop computers come with internal SD card readers, but in many cases an external card reader must be purchased. These card readers vary in design. Simple SD card readers are shaped like a USB flash drive with a built-in slot for SD card insertion. Multicard readers have slots for SD, as well as other memory card formats, allowing the user to work with multiple memory formats more efficiently.