OneDrive is a free online file storage service that allows users to store and access their files from any device. Users can add files to OneDrive by dragging them into the OneDrive folder on their computer or uploading them directly from the OneDrive website. Files stored in OneDrive will automatically sync across a user's devices with the OneDrive app installed. The OneDrive app also allows users to backup photos and videos from their phone to OneDrive to access on other devices and prevent data loss if their phone is lost.