A memory card is a small, portable storage device used to save digital data. Commonly found in devices like cameras, smartphones, and tablets, they allow users to store photos, videos, music, and other files. Memory cards come in various formats, such as SD cards and microSD cards, each with different storage capacities and speeds. These cards are essential for expanding the storage of devices that have limited internal memory. They are easily removable, making it simple to transfer data between devices. Many memory cards also have built-in security features to protect the stored information from unauthorized access.