A scratch disk is a temporary storage area on a computer’s hard drive or SSD that is used as virtual memory when the system runs low on available RAM. It allows software to use disk space as a substitute for memory, helping applications continue to function when handling large or complex tasks.
In photography and image editing, scratch disks are commonly used by programs such as photo editing software when working with high-resolution images, multiple layers, or large files. A fast scratch disk can improve performance, reduce lag, and help maintain smooth workflow when editing demanding photographic projects.