A finite-state machine is a way of describing what something can do based on the different states it can have.
For example, imagine you have a light switch. It has two states – on and off. When you press the switch, it will move from one of these states to the other. This is an example of a finite-state machine.
Communicating finite-state machines are connected to each other so that they can understand and send messages. This can help them work together to make decisions.
For example, if you have two machines that need to decide whether to turn a light on or off, you can use a communicating finite-state machine. The machines would talk to each other, telling each other their states, and then they would decide together which one needs to change. This is how machines work together to make decisions.