How to update your device's operating system (OS)?

Settings > General > Software Update > Download and Install.

More info: https://support.apple.com/en-us/HT204204

Settings > About device > System Updates > Check for Updates > Update to download and install the latest Android version.

More info: https://support.google.com/android/answer/7680439?hl=en

Choose System Preferences > Click Software Update to check for updates > If any updates are available, click the Update Now button to install them.

More info: https://support.apple.com/en-us/HT201541

Select the Start button > Go to Settings > Update & Security > Windows Update.

More info: https://support.microsoft.com/en-us/help/4027667/windows-10-update