what is the comparison between PID controller and PLC?

Dear all
what is the comparison between PID controller and PLC?
when i can use PID controller?,
when i can use PLC?,
and
when i have to use PID and PLC togather?

PLEASE REPLY
with my besr regards

PID control for continous process control that solves well with 3 term control.
PLC for discrete control, and state logic.
When you have both, use both.

PID is an algorithm. The most common is a Temperature Controller. A Temperature Controller with a PID feature is commonly called a PID controller. A PID Controller is not limited to temperature. You can use it for any process that needs the same type of control as a heater.
The proper term for a PID Controller is Process Controller.

A PLC is a computer that is designed to control machines. PLC's can have many options. One of the options is PID Control. This means you can have a PLC with a PID Controller built in as one of the features.

Now many PLCs are available with PID controllers. In PID u cannot program the Logic. U can set the parameters.