It stands for Secure Digital and is a memory card format developed by the SD Association. SD cards are currently divided into three tiers, describing the storage capacity range: Standard SD cards have a maximum capacity of 2GB; SDHC (High Capacity) cards have a capacity range of 4GB to 32GB, and SDXC (Extended Capacity) cards have a capacity range of 64GB to 1TB (capacity Eventually up to 2TB).

SD cards are used in a variety of mobile electronics, computers, cameras and smart devices. For example, if you shoot 4K video, you'll most likely want an SDXC card, as its maximum capacity of 2TB is sufficient for optimal video recording performance.