Brain-computer interfaces (BCIs) connect the brain to external devices, enabling direct communication between neural activity and technology. BCIs work by detecting and interpreting brain signals, often through electroencephalography (EEG) or implanted electrodes. These signals are translated into commands that can control computers, prosthetics, or other devices. BCIs hold promise for aiding individuals with disabilities, enhancing cognitive functions, and facilitating advanced human-computer interaction. Research focuses on improving signal accuracy, interface usability, and real-time processing. The technology aims to bridge the gap between human thought and machine execution, revolutionizing fields such as medicine, communication, and entertainment.