microSD cards are small, portable storage devices used to expand the memory of various electronic devices, such as smartphones, tablets, and cameras. They are designed to hold data like photos, videos, music, and apps, making it easier to manage and transfer files. These cards come in different storage capacities, ranging from a few gigabytes (GB) to several terabytes (TB). microSD cards are widely used due to their compact size and compatibility with many devices, often requiring an adapter for use in standard SD card slots.