As new threats are detected, Samsung updates the security policies on the device to prevent these new attacks.
This feature is always enabled and allows your device to be protected after a threat is detected, instead of waiting for the next scheduled software upgrade.
Installing this update ensures that you have up-to-date protections for your device.
For more on SE for Android or for tips on securing your device, please visit https://www.samsungknox.com/products/knox-workspace/how-to/lock-down-android.