Fossils are the preserved remains or traces of ancient life, and they come in several types. The most common type is body fossils, which include bones, teeth, and shells. These fossils provide direct evidence of what organisms looked like and how they lived. Another type is trace fossils, which record the activities of organisms, such as footprints, burrows, or feces. These fossils help scientists understand the behavior and movement of ancient species, offering insights into their environment and interactions with other organisms.