Editing Automata theory (section)

===Informal description===
An automaton ''runs'' when it is given some sequence of ''inputs'' in discrete (individual) ''time steps'' (or just ''steps''). An automaton processes one input picked from a set of ''[[Symbol (formal)|symbols]]'' or ''letters'', which is called an ''input [[alphabet (computer science)|alphabet]]''. The symbols received by the automaton as input at any step are a sequence of symbols called ''words''. An automaton has a set of ''states''. At each moment during a run of the automaton, the automaton is ''in'' one of its states. When the automaton receives new input, it moves to another state (or ''transitions'') based on a ''transition function'' that takes the previous state and current input symbol as parameters. At the same time, another function called the ''output function'' produces symbols from the ''output alphabet'', also according to the previous state and current input symbol. The automaton reads the symbols of the input word and transitions between states until the word is read completely, if it is finite in length, at which point the automaton ''halts''. A state at which the automaton halts is called the ''final state''.

To investigate the possible state/input/output sequences in an automaton using [[formal language]] theory, a machine can be assigned a ''starting state'' and a set of ''accepting states''. Then, depending on whether a run starting from the starting state ends in an accepting state, the automaton can be said to ''accept'' or ''reject'' an input sequence. The set of all the words accepted by an automaton is called the ''language recognized by the automaton''. A familiar example of a machine recognizing a language is an [[Electronic_lock#Numerical_codes,_passwords,_and_passphrases|electronic lock]], which accepts or rejects attempts to enter the correct code.