Originally Posted by
RustBeltRaw
High and low-level formats as executed in your camera are probably similar to deleting versus formatting the data on a hard drive. A high-level format probably erases the headers on each image file, essentially removing the piece of data that tells your camera or computer that the data following the header is an image. A low-level format probably deletes the header and the data for each image, over-writing it with either random bits or a pre-defined pattern. Deleted data can sometimes be recovered. Formatted data cannot. Functionally, they're essentially identical, but a high-level format is much faster.