Windows devices may get new functionality at different times as Microsoft delivers non-security updates, fixes, improvements, and enhancements via several servicing technologies—including controlled feature rollout (CFR). Windows will let you know if you need to restart your device to complete an update, and you can choose a time that works best for you to complete that update.

For details, please refer to the link below:
https://support.microsoft.com/en-us/windows/get-the-latest-windows-update-7d20e88c-0568-483a-37bc-c3885390d212