A petroglyph is a rock drawing that has been carved into the rock or created by weathering the rock away. Either way, it is a carving of some kind on a rock. The word comes from a French word that was spelled pretty much exactly the same way, but the French word comes from the Greek for “stone” and “carving”.
This is one of the few times that a word can literally be translated at the roots to what it really is. It can be carved in various kind of stones, and there’s another kind of petroglyph. It’s called a living petroglyph. This is when the picture is carved into a rock that is attached to other rock - such as the face of a cliff or part of a cave wall.