What is the meaning of counter weight in a forklift? and how can l identify a controller in a forklift?

the counterweight, this is load limit of a forklift, that will hold the load in forklift.
but it doesn't mean that the counterweight is2ton you can carry also2 ton, it depends on the width of your load in front, the longer you occupy the fork the lesser weight you can load.

It is the weight to be lifted by the fork lift.
and you can controll by power output of a machine.

A counterweight is the one that balancing the load weight and the machine.
Please which part of controller did you meaning