Hello All
I'm learning to use the Arduino board for the first time, I'm tyring to use the Arduino to pass current to a linear actuator 12 v and switch off and on the actuator from the program in the Arduino board.
Can any one help me how to achieve this I have been trying to learn it I could not find any tutorials regarding this.
The Arduino can't provide a lot of current. And can certainly not switch 12V by it's self. So what type of actuator are we talking about? Type, link and specs are needed to give you a good answer 
The Actuator has a 12v supply adapter and I have a breadboard how to connect the bread board to the Actuator and power supply adapter. Can you please help me regarding this. How to control the Actuator from the Arduino using the program.
Like I said, not without details
Okay here are the details and specs of the actuator
Linear Linear Actuator - Power Door Lock Mechanism for Electronics Circuit RC-A-742
link to the actuator https://www.amazon.in/Robocraze-Linear-Actuator-RC-742/dp/B07B3JPGCT/ref=sr_1_3?keywords=robocraze+actuator&qid=1564576009&s=gateway&sr=8-3
I have a 12v dc power adapter to connect to the actuator, how can I use Arduino board to on and off the Actuator ? Kindly help me
Not to much details unfortuanally. But a simple transistor (prefereable a MOSFT) circuit on the low side (GND side) will do. Just Google "Arduino transistor" or "arduino mosfet" and get loads of examples
This actuator (correct link: https://www.amazon.in/Robocraze-Linear-Actuator-RC-742/dp/B07B3JPGCT) uses a reversible motor and draws significant current but must only be activated for about a second at most. To reverse it you could use an "H-bridge" but I am not familiar with them, or a common dual relay module.
Thanks guys do I need to use relay or the Mosfet idea ?
It would probably be easiest to do with relays, as you will want to be able to run the motor in both directions. That relay module Paul posted would be great for this. I think you can wire up the relays to provide reverse voltage as well as forward. The relay module will accept 5 volt control from the Arduino and will provide 12 volts to the motor.
Yeah, relay will work as well. Downside, mechanical and "loud".
Tips if you want to go that route, get a 12V relay module. Least change of trouble if you already have a 12V supply.
septillion:
Yeah, relay will work as well. Downside, mechanical and "loud".
If that is your concern, you clearly have not heard the actuator operating! 
Try to find the motor coil wires and measure the resistance .
This would be helpful in the absence of any current rating info.
If you know how to measure current, measure the motor current.
I assume it's in the range of 500 to 800 mA.
What you want to know is how much current do you need to source for the lock.
What are the specs for your 12V supply ?
Leave jumper on to run relays from Vcc 5V supply