What is the difference between incremental and differential backups, and which one should a developer choose?

Choosing the right backup strategy directly affects archive creation speed and the amount of consumed disk space. Developers and system administrators often have to choose between incremental and differential backup types. Understanding how each method works helps optimize the storage process for large volumes of source code and databases.

A full backup always copies absolutely all selected files and databases, regardless of whether they have changed or not. Since this process requires a lot of time and disk space, full copies are made infrequently, for example, once a week. On other days, either incremental or differential methods are used to save only the modified data.

An incremental backup saves only those files that have changed since the creation of the last backup of any type. This approach ensures maximum archive creation speed and a minimum backup file size. However, the process of restoring data from incremental copies is the longest, as the system first needs to restore the full copy and then sequentially apply each incremental archive.

A differential backup copies all changes that have occurred since the last full backup was created. The size of such archives gradually grows from one day to the next because they duplicate files that have changed for several consecutive days. Data recovery is significantly faster because only the last full copy and the last differential file are required.

For developers, a hybrid scheme is often the optimal choice. Creating a weekly full backup combined with daily incremental copies saves disk space. However, if it is critical to quickly restore the working environment after a failure, it is better to choose the differential method as a daily supplement to the full archive.