Brain-Computer Interface (BCI) is a technology that enables direct communication between the human brain and external devices, such as computers or prosthetics. By interpreting brain signals, BCIs allow users to control devices or software without physical movement, often aiding those with mobility or communication impairments. This innovative field combines neuroscience, engineering, and computer science to translate neural activity into actionable commands, opening new possibilities for assistive technology, gaming, and even security applications.