In electrochemistry, "concentration cell" refers to a device where two half-cells are connected with a salt bridge. Synonyms for this term can include "diffusion cell," "gradient cell," or "separation cell." Each of these terms indicates the process of concentrated matter moving towards areas of lesser concentration. In a concentration cell, the half-cells have different concentrations of the same electrolyte, which provides the driving force for electron transfer. These cells are crucial for various industrial applications, including metal corrosion studies and battery research and development. Concentration cells are also essential for understanding biological phenomena, such as ion distributions across cell membranes.