Kriya in Sanskrit means completed action. It is also a cleansing technique. There are six kriyas which helps to cleanse various internal organs.
Trataka is also called yogic gazing. It is a practice where the gaze is fixed on an object or point. Trataka is an eye exercise to improve, gazing, focusing and defocusing while Kapalabhati is for cleansing frontal lobe.
Trataka is a Sanskrit word, which means ‘to look’ or ‘to gaze’. As such, this meditation technique involves starting with a single point of focus. There are various techniques of Tratakas.