If it is at all possible, you should read the details of the update just to verify that it is something that is genuine, and also to know what it is going to affect. If I had a nickel
for every time I heard "My computer isn't working anymore, there was an update but I don't know what it was..."
The new code could make your device, program or app run better. It might add new functionality, a better way to hide Solitaire from your boss. Or it might make things more secure.
Think of this as the big red idiot light on the dashboard of your car, you wouldn't drive for months with it blinking at you, right?
Follow the advice of your Operating System and activate your updates.