Some file recovery apps, including Magic Uneraser Home, offer a quicker scan feature, plus a deep scan that searches the entire drive, which can take quite some time depending on the size of the drive & its speed. Magic Uneraser Home, like other file recovery apps, looks for chunks of data on the drive, then attempts to put them together into the files that were originally stored. Leaving data in place doesn't work as well with SSDs however, since data has to be removed before it can be replaced in a 2nd step, so deleted data may be removed proactively to speed up future writes to the drive. On a regular hard drive that data will remain until some other data is written to the physical space it occupies. When a file is permanently deleted - not just sent to the Recycle Bin - it's removed from that index, but the stored data remains. Data is stored in small chunks, with tables that act as an index, listing which of those small chunks of data make up which files, & where each is physically located.
