What is the expected stratigraphic layers called?

The expected stratigraphic layers are commonly referred to as "strata." Each layer represents a specific period of geological time, with the oldest layers typically found at the bottom and the youngest at the top, following the principle of superposition. These layers can vary in composition, color, and fossil content, providing insights into the Earth's history and past environments. In sedimentary geology, these layers are crucial for understanding processes like sedimentation and erosion.