Automatic updates ensure your Windows installation stays current with security patches without requiring you to remember to check manually. A computer that has not been updated is a computer with known, unfixed vulnerabilities. Enabling automatic updates is one of the simplest and most important things you can do.
Windows will sometimes need to restart to apply updates. You can schedule when restarts happen under the Windows Update settings. Choose a time when you are typically not using the computer, such as early morning. If Windows needs a restart, it will show a notification rather than restarting without warning during your active hours.
Windows Update does not cover every program on your computer. Make sure you also enable automatic updates in your web browser, antivirus software, and any other applications you use regularly. Web browsers in particular release frequent security updates and should always be kept current.