A memory card is a storage of digital data used most often for the storage of digital images in digital cameras (APN) for backup parts on video game consoles, but also in MP3 music players or professional electronic equipment such as total stations.
Generally these cards are incompatible with each other, a memory card for Sony console does not work for a Nintendo console for example. In the field of digital imaging, the cards are incompatible in the sense that a digital camera usually uses only one type of card. Digital cameras support more than one type of card figures are exceptions.
There are adapters to read a card type : for example, reading a CompactFlash on a PCMCIA port. However, these adapters can only read a card that is compatible.