S&W M&P'S with / without Manuel safety ?
The trigger on the M&P line of guns is comparable to the Glock trigger.
They are both considered "Safe Action" triggers.
Fingers must be placed on the trigger for the gun to go bang.
Some models of the M&P line have an external safety that functions like the safety on the 1911 style guns.
If it is up, the weapon is on safe.
If it is down, the weapon is ready to fire.
Smith and Wesson had to add the external safety per request from some LE departments who wanted that extra step before the weapon could be discharged.
Treat all M&P handguns as you would a Glock and things will be just fine!