To copy the document, record or image being worked on to a storage medium. If the file has already been created on the hard disk, saving updates the file by writing the data currently in memory (RAM) to the disk. All modern applications prompt the user to save data upon exiting if the user has made any changes to them.

Save to Disk
All processing is done in memory (RAM). When the processing is completed, the data must be placed onto a permanent storage medium, which is generally the hard disk. In the past, it might have been magnetic tape. See Save As.