Non-deterministic finite automata

Question

Could someone explain why this(the automata in the picture)is a NDFA? Is it because it only has one initial state or because there are several arrows with the same symbol that arrive at the same state? I dont quite understand if one of those things define it as an NDFA?

Answer 1

It's non-deterministic because q1 has two different transitions on # .

After (# , the machine is in states q1 and q3 , and will accept all of @) , #@) , ##@) , etc.

State q3 is, however, redundant. You could just remove it to produce a DFA that accepts the same language.