How to connect laser module to cnc sheild v3.0

Grumpy_Mike:
Not sure that you understand the difference between the two. TTL is a voltage specification for logic which is basically 0V and 5V for the two voltage levels. PWM, is pulse width modulation and consists of turning a signal on and off. The ratio of on to off determining an equivalent voltage. See http://www.thebox.myzen.co.uk/Tutorial/PWM.html

So this questionMakes no sense.
With a 12V power supply capable of at least half an Amp. Make sure the ground of the power supply is connected to the ground of the Arduino.

Im sorry i can't understand about the ttl and pwm.

In my case the laser has 3 pins. VCC GND PWM

https://goo.gl/images/uYe4Sq

So how do i connect this laser to my cnc sheild?

Vcc to 12v external power +
and
GND to external power -
Then
PWM is connect to D11 pin of arduino

Is this correct?

Please explain this..