What is a petroglyph?

A petroglyph is an image created by removing part of a rock surface by incising, picking, carving, or abrading, as a form of rock art. Outside North America, scholars often use terms such as "carving", "engraving", or other descriptions of the technique to refer to such images. Petroglyphs are found worldwide, and are often associated with prehistoric peoples. The word comes from the Greek prefix petro-, from πέτρα petra meaning "stone", and γλύφω glýphō meaning "carve", and was originally coined in French as pétroglyphe.

Another form of petroglyph, normally found in literate cultures, a rock relief or rock-cut relief is a relief sculpture carved on "living rock" such as a cliff, rather than a detached piece of stone. While these relief carvings are a category of rock art, sometimes found in conjunction with rock-cut architecture, they tend to be omitted in most works on rock art, which concentrate on engravings and paintings by prehistoric or nonliterate cultures. Some of these reliefs exploit the rock's natural properties to define an image. Rock reliefs have been made in many cultures, especially in the ancient Near East. Rock reliefs are generally fairly large, as they need to be to make an impact in the open air. Most have figures that are larger than life-size.