A railway signal is a visual indicator used to control train movements on a railway track. It helps ensure safety by informing train operators when to stop, proceed, or slow down. Signals can be found at various locations, including junctions, crossings, and stations, and they use different colors and shapes to convey specific instructions. There are two main types of railway signals: fixed signals and hand signals. Fixed signals are stationary and display lights or boards, while hand signals are given by railway personnel to direct train movements. Both types play a crucial role in maintaining an organized and safe railway system.