A major version of iOS tends to be released every time a new type of iPhone is launched (usually once a year), with minor changes throughout the year as needed. The operating system on iOS devices can be updated through iTunes or Finder (from macOS Catalina), or on iOS 5 or later, using over-the-air updates.Have a quick read of Can my iPhone get iOS 14? If you want to install iOS 14 on your iPhone (not the beta version) we explain how to get iOS 14 on your iPhone First check that your device is compatible. But what if you don't want to wait that long to try out the new features? You need to install a beta.
