Hello,
To continue receiving security and quality updates, Microsoft recommends that you update to the latest version of Windows 10. There are different types of windows update, such as feature update, quality updates, etc...
Feature updates: Released annually. Feature updates add new features and functionality to Windows 10. Because they're delivered frequently (rather than every 3-5 years), they're easier to manage.
Quality updates: Quality updates deliver both security and nonsecurity fixes. Quality updates include security updates, critical updates, servicing stack updates, and driver updates. Quality updates are cumulative, so installing the latest quality update is sufficient to get all the available fixes for a specific feature update, including any out-of-band security fixes and any servicing stack updates that might have been released previously.