When protecting your virtual or physical machines, you can choose to protect using Full backup or incremental
The following image is from the Physical backup wizard, although the same options are available for the vSphere Virtual Machine backup type.
If you are unsure, this may help you to decide which best fits your needs:
(Factors can impact the results shown above. This information is provided as an indicator only)
Incremental backup for Windows Physical machines is currently unsupported