When recovering with the latest incremental backup, you would need the Full and every Incremental backup for that period. For the restoration of the latest differential backup, you only need the Full and the last Differential backup.
For example, if you want to recover ‘Incremental2.PBD’, you will use ‘Full.PBD’, ‘Incremental1.PBD’ and ‘Incremental2.PBD’ to finish the restoration.
However, when recovering ‘Differential2.PBD’, just need ‘Full.PBD’ and ‘Differential2.PBD’ to restore the files.