That's a really good question.
My answer was this:
FEAR = negative emotions... doubt, low energy, resistance, back and forth second guessing, thoughts of "who am I to think I can do this?", physically causes frowning
TUG (true ultimate guide or intuition) = positive emotions... high energy, a sense of peace with the decision, resolution that it's right for you right now without guilt, breathing easier with the decision, physically causes smiling
These are just a few ways to differentiate between fear and intuition. Also fear is a mechanism that holds us back from pushing through to the next level. Intuition, on the other hand, propels us forward even if it feels uncomfortable (it has our back).
Some life decisions are incredibly hard to make, and scary, but when you sit with the question and listen to your inner voice (not all that noise of 'what will the external world think', but really listen to the whisper inside you)... you can hear your truth. Fear is loud and distracting. It makes a big fuss. It creates all kinds of drama. Fear is impulsive and likes to be in control. And although intuition looks for opportunities to get your attention and pokes you repeatedly, it waits patiently for YOU to take control.
But make no mistake, BOTH are temporary. Just because you choose to follow your tug, it will only guide you to the next step... then you have to go deep and listen some more and follow it again and again. Intuition is not a one-hit wonder nor will it solve all your problems in one fowl swoop. It will merely lead you down the right path for now... based on what you need at this point in time.
Going for that job might be exactly the right decision... only to find out two months later you're guided to do something completely different. One has to be open to all the twists and turns of the journey. The idea is to make decisions that cultivate a 'feel good' vibe. Following your tug will do that far more often than letting fear take the lead.