Nondeterministic finite automata (NFA) is a finite automata that can be in several states at once (several variable)
The inverse of Nondeterministic automata (NFA) is deterministic finite-state automata (DFA) that cannot be in more than one state at any one time.
Nondeterminism allows to program solutions to problems using a higher-level language.
The nondetemministic finite automaton is then compiled into a deterministic automaton.