The first number is called systolic blood pressure because it indicates blood pressure during the heartbeat (systole), and the second number is called diastolic blood pressure because it indicates blood pressure while the heart is relaxed (diastole).
पहली संख्या को सिस्टोलिक ब्लड प्रेशर कहा जाता है क्योंकि यह हृदय के धड़कने (सिस्टोल) के समय के ब्लड प्रेशर को दिखाता है ।