A delta is a landform formed at the mouth of a river, where it deposits sediment as it flows into a slower-moving or standing body of water, such as an ocean, sea, or lake. Deltas are characterized by their branching network of distributaries and are classified based on the dominant processes that shape them: river-dominated, wave-dominated, or tide-dominated. Deltas are significant in sedimentology, coastal geomorphology, and are often fertile areas for agriculture.
Reference: Coleman, J. M., & Wright, L. D. (1975). “Deltas: Processes of Deposition and Models for Exploration.” Continuing Education Publishing Co.