What's motorcycle certification?

Is it similar to cars' certification where they certify that it is safe, like all lights, turn signals, brakes, ball joints are fine? or is it something different?

I'm unsure of where you are from, but in Pennsylvania, US what you just described is called "Inspection". Here, certification is what they put on your Driver's License to show what types of vehicles you are permitted to drive. Motorcycles also have to be "inspected" in PA, which is just verifying that the bike is in safe, working order.

I hope that's what you were looking for.

yeah that's pretty much it, I assume unlike cars, motorcycles do not have to go through emission tests

Again, I speak for PA... Bikes do NOT have to pass emissions tests. I live in one of 9 counties that require emissions testing, and my bike does not get tested.