I looked it up and think this definition is interesting:

“Psychologists often make a distinction between fears and phobias. A fear is an emotional response to a real or perceived threat. A phobia is similar to a fear with one key difference: the anxiety they experience is so strong that it interferes with their quality of life and/or their ability to function.”

I used to be immensely afraid of lizards, so much that I would jump and shriek if one came near me. I don’t know where that would fit; fear or phobia by this definition. It wasn’t a real threat- totally harmless. And it didn’t hinder my life for more than a few seconds.