When to Use Mealy or Moore?

Moore machines may be safer to use, because they change states on the clock edge (if you are using DFF logic for present and next state), whereas Mealy machines are faster, because the state is dependent on the input. Thus, the state can change asynchronously. This comes down to predictability vs raw speed.

How do you know if its Moore or mealy?

Mealy machines react faster to inputs. They generally react in the same clock cycle. In Moore machines, more logic is required to decode the outputs resulting in more circuit delays. They generally react one clock cycle later.

What is the basic difference between mealy model and Moore model?

In Mealy Machine one state may have more than one output. In Moore Machine one state is associated with only one output. 4. The output may change either when input changes or when the flip-flop change state.