It installs an app named Install Version Name.
For example, if your Mac came with macOS Big Sur, it will not accept installation of macOS Catalina or earlier. The version of macOS that came with your Mac is the earliest version it can use. Learn how to upgrade to macOS Big Sur, the latest version of macOS. Apple recommends that you always use the latest macOS that is compatible with your Mac. To get the latest features and maintain the security, stability, compatibility, and performance of your Mac, it's important to keep your software up to date.
