Geomorphology is the study of landforms and the processes that shape them. It is a branch of physical geography that analyzes relief features at different dimensions and scales. Relief features are organized into three orders based on size: first order includes continents and ocean basins shaped by plate tectics; second order consists of structural landforms like mountains and plateaus formed by constructional forces; third order comprises micro-level erosional and depositional landforms developed on second order features by exogenic processes like rivers and glaciers. Process geomorphology examines specialized subfields defined by the dominant shaping process, such as fluvial, glacial, coastal and karst landforms.