Other forms: restored, restoring, restores
To restore is to bring files back from a spare copy. Restore from backup, restore the database, a restore point.
Backing up and restoring are the two halves of the same job, and a backup nobody has ever tested a restore from is not really a backup. Elsewhere, to restore is to bring something back to its former state: restore a painting, restore order, restore confidence. And it means to give something back: restore it to its owner. Note restoration, and factory reset, which restores a device to how it left the factory.
Latin restaurare means to rebuild or renew. It gives English both restore and, through French, restaurant — a restaurant was originally a restorative broth sold to revive you, and the shop took the name of the soup.
Latin
restauro
Old French
restorer
Middle English
restoren
English, today
restore
From Middle English restoren, from Old French restorer, from Latin restauro. by surface analysis, en + re + store.
Etymology from Wiktionary, CC BY-SA