srjecsSRJECSSRJECS2788-9408https://doi.org/10.47310/srjecs.2022.v02i01.003A Complete Review of Brain Computer InterfaceSushmithaNSudarshanRamakanthKumarPThe technology of Brain Computer Interface (BCI) is a rapidly growing research field with vast applications. BCI acts as a bridge between a human brain and the machine-like computer. The main purpose of BCI system is to enable the people with disability to interact with outside world. The electrical signals captured from the brain are processed to remove the noise and artifacts. The features of the processed signal are extracted, classified and later translated into the device commands in order to execute the intent of the user. This paper furnishes the basics of BCI, different ways of signal acquisition, overview of the BCI system, its applications and challenges.