An incremental backup is a data protection method that saves only the changes made since the last backup. This means that after the initial full backup, subsequent backups only capture new or modified files. This approach is efficient in terms of storage space and time, as it reduces the amount of data that needs to be copied. For example, if a user has a full backup of their files on a hard drive, the first incremental backup will save only the files that have changed since that full backup. This process continues, allowing for quick recovery of data while minimizing the backup window and resource usage.