Chemotaxis is the movement of an organism or cell in response to a chemical stimulus. This process allows cells, such as bacteria or white blood cells, to navigate toward beneficial substances like nutrients or away from harmful ones, enhancing their survival and function. In chemotaxis, cells detect chemical gradients in their environment and move accordingly. For example, bacteria can swim toward higher concentrations of food or away from toxins. This behavior is crucial in various biological processes, including immune responses and developmental biology, where cells must locate specific signals to perform their roles effectively.