Storage hard disks (HDDs) and SD cards are non-volatile data storage solutions, with HDDs typically used for large-scale, high-speed, permanent internal storage (up to 20+ TB) in computers. SD cards (Secure Digital) are small, removable flash memory cards primarily used for portable, lower-capacity storage in cameras, phones, and tablets.

A traditional storage device that uses spinning magnetic disks (platters) to read and write data.

Primary storage in desktop computers and laptops, known for high capacity and lower cost per gigabyte.

Ranges from hundreds of GBs up to over 20 TB.

A compact, non-volatile flash memory card used for storing and transferring data between portable devices.

Commonly used in digital cameras, smartphones, drones, and tablets to expand storage.

Varies by standard: SD (up to 2GB), SDHC (up to 32GB), SDXC (up to 2TB), and SDUC (up to 128TB).