A finite automaton is an automaton that has a set of states and its control moves from state to state in response to external inputs.
It has a start and an end state and there are only a finite number of states
A formal de definition of a finite automaton is whenever:
An automaton implementing a lexer modeling the recognition of the keyword then
where:
The advantage of having only a finite number of states is that we can implement the system with a fixed set of resources
Example:
example: A on/off button