Petroglyphs and Pictographs

What's the difference between a petroglyph and a pictograph?

Found throughout southern Utah, a petroglyph is an image carved, incised or scratched into stone. A pictograph is a painting on stone, using natural pigments.

Pictographs are typically found only in caves or other areas where they can be protected from the elements of sunshine, wind-blown sand and precipitation.

Rock art has survived hundreds, even thousands of years, but it can't survive vandals or even repeated touching -- the oil from fingertips damages rock art.