There are three main types of memory cards: SD, microSD, and CompactFlash. Each type has its own advantages and disadvantages. SD cards are the most common type of memory card. They are typically used in digital cameras and camcorders. SD cards are available in a variety of sizes, from 2GB to 32GB. MicroSD cards are smaller than SD cards, but they offer the same type of storage. MicroSD cards are often used in smartphones and other portable devices. MicroSD cards are available in sizes from 2GB to 64GB. CompactFlash cards are larger than SD cards, but they offer more storage space. CompactFlash cards are often used in professional-grade digital cameras. CompactFlash cards are available in sizes from 4GB to 128GB.