An Incremental Backup will backup all the files that have changed since the last Full Backup (the first time it is run after a full backup was previously completed) or after an Incremental Backup (for the second backup and subsequent backups) and sets the archive bit to 0. This type of backup
Takes less time during the backup phase but it will take more time to restore.

Differential Backup—Backs up the files that have been modified since the last Full Backup. The archive bit does not change. Takes more time while the backup phase is performed and take less time to restore.