Systolic blood pressure: Systolic blood pressure is the pressure measured when the heart beats and pumps blood through the arteries. Systolic blood pressure is higher because the blood pressure is high when it is pumped through your arteries.
Diastolic blood pressure: Diastolic blood pressure is the blood pressure between the heart beats when the heart is not in pumping state. When heart is not pumping the blood, the pressure is lower.
Sphygmomanometer: It is a device used to measure blood pressure.