What is incremental backup?
Incremental backup stores all data changed since the last full, differential or incremental backup. It takes the least time for backing up, but a lengthy job for restoring.
The backup is the fastest and it saves storage space but the recovery is the slowest ( compared with full backup or differential backup ). Each backup increment can store a different version for databases but to restore the latest version of a database, the last full backup and all of the incremental backups must be found first.
In the image below you can see an example on how a backup job running four times would look like when using incremental backup:
When restoring from incremental backup, you need the last full backup and all of the incremental backups you've made since the last full backup. So it takes more time to restore.
Click here to read more about enable the binary logs for MySQL incremental / differential backup