ICloud

iCloud is a cloud storage and computing service launched by Apple on October 12, 2011. By July 2013, the service had 320 million users.

Description
The service provides its users with means to store data such as documents, photos, files and music on remote servers for download to iOS, iPadOS, Macintosh or Windows devices, to share and send data to other users, and to manage their Apple devices if lost or stolen.

The service also provides the means to wirelessly back up or sync iOS devices directly to iCloud, instead of being reliant on manual backups to a host Mac or Windows computer through iTunes. Service users are also able to share and sync photos, music, and games instantly by linking accounts via AirDrop wirelessly.

It replaced Apple's MobileMe service, acting as a data syncing center for email, contacts, calendars, bookmarks, notes, reminders (to-do lists), iWork documents, photos and other data.

iCloud Drive
All photos, music and other files synced to iCloud will appear in the iCloud Drive, an in the Files app. The iCloud Drive can contain files that are also synced to the "On My iPad". The files you keep safe in iCloud Drive can be accessed easily. You can access all your files from the Files app on iOS and iPadOS, the Finder on your Mac, File Explorer for Windows PCs, or iCloud.com.

The iCloud Drive allows you to organize files into folders, rename them and tag them with different colors.

iCloud Drive makes it fast and easy to work with others from anywhere. Sending a private link to a friend will allow that friend to gain instant access to the folders and files you’ve chosen to share. You can change the settings that control whether they can view, share, or edit each file, and you can change these settings at any time. Anyone you choose to send the link to can participate from anywhere since it works across iPhone, iPad, Mac, Windows PCs, the web, and now Android.

Updating apps with iCloud
Any built-in app synced to iCloud, like Mail, Files, Safari, Calendars and iWork apps can be refreshed and updated automatically. If there is a change to any of the files, the change will appear on every single device connected to the file link. On iWork apps, live updates on each device are held, and every single collaborator will know there's an edit. In iMessage, iCloud stores each conversation, and you can move on where you left off even with another device with the same Apple ID.

iCloud Backup
When you get a new device and sign in to iCloud with your Apple ID, all your documents, photos, settings, files, music and whatnot get transferred seamlessly to your new device. This is possibly the mobile alternative to Time Machine.