There are four valves in the heart. Aortic, Pulmonary, Tricuspid, and Mitral valves.
The aortic valve rests in between the left ventricle and the aorta.
The pulmonary valve rests in between the right ventricle and the pulmonary artery.
The tricuspid valve rests in between the right atrium and the right ventricle.
The mitral valve rests in between the left atrium and the left ventricle.