An incremental backup is a data backup method that records only the changes made to files or data since the last backup. This method is widely used in modern IT systems due to its efficiency in saving time, storage space, and bandwidth compared to full backups, which duplicate all data regardless of changes.

The process begins with a full backup as the baseline. Subsequent incremental backups save only the data that has been modified or created since the most recent backup, whether it was a full or another incremental one. For instance, if a full backup occurs on Sunday, and incremental backups are performed on Monday, Tuesday, and Wednesday, each day's backup will only include files changed since the previous day's backup.

Incremental backups offer several advantages. They are faster to perform and require less storage space, making them ideal for organizations managing large volumes of data. Additionally, they reduce strain on system resources during backup operations, which is particularly valuable for real-time or always-on systems.

However, restoration using incremental backups can be complex. To recover the full system, the process requires the initial full backup and all subsequent incremental backups to reconstruct the data. This dependency on multiple backup files increases the potential for failure if any file is corrupted or lost.

To address this challenge, organizations often combine incremental backups with differential backups or use advanced tools like backup management software to simplify restoration. Incremental backups remain a core strategy for effective data protection in enterprise environments.