Students learn why fossils are often referred to as "windows to the past." The basic requirements for fossil formation are identified. Examples of various fossils highlight different types of fossil preservation, including petrification, imprints, molds and casts, freezing, amber fossilization, and preservation in tar pits. Finally, various uses of fossils are discussed. Additional terminology and concepts: cement, paleontology, fossil fuels, preserved remains, paleontologist, sediments, and limestone.