Both DRM SDK and DRM wrapper enables DRM protection to your content, while wrapper is a repacking process, and SDK requires source code integration.
DRM Wrapper is the recommended approach when it comes to DRM solutions, as it handles error conditions and shows responding error messages. However, in some situations, DRM wrapper may encounter compatibility issues, in such case you should use DRM SDK as the alternative solution.
DRM SDK provides a set of API to validate if the user has ownership of your content. You need to handle certain conditions DRM SDK, and provide corresponding error messages, for example why prompt to users when they cannot run your content and why (ownership, exceeding specified concurrency).