Windows 10 updates are cumulative. The monthly security release includes all security fixes for vulnerabilities that affect Windows 10, in addition to non-security updates. The updates are available via the Microsoft Update Catalog. For information on lifecycle and support dates for Windows 10 operating systems, please see Windows Lifecycle Facts Sheet.
A list of the latest servicing stack updates for each operating system can be found in ADV990001. This list will be updated whenever a new servicing stack update is released. It is important to install the latest servicing stack update.
In addition to security changes for the vulnerabilities, updates include defense-in-depth updates to help improve security-related features.
Customers running Windows 7, Windows Server 2008 R2, or Windows Server 2008 need to purchase the Extended Security Update to continue receiving security updates. See 4522133 for more information.
Known Issues You can see these in more detail from the Deployments tab by selecting Known Issues column in the Edit Columns panel.
For more information about Windows Known Issues, please see Windows message center (links to currently-supported versions of Windows are in the left pane).