Where do earthquakes form? I would like to know the type of environment where an earthquake would most likely occur. I do not need specific places.

Earthquakes can form anywhere in the world. Earthquakes happen in result of tectonic plates moving. For example, the ring of fire. The majority of the world's earthquakes happen on the ring of fire; It surrounds the pacific ocean. That's why you generally see on the news that there was an earthquake in Japan or an earthquake Alaska because those places are right on the rim of the tectonic plate (ring of fire)