Video narration
Does a suction pump really grab water and pull it upward? Think of drinking through a straw: lower the pressure inside, and air around the drink pushes it up. The straw isn't pulling the liquid by itself. A hand pump uses the same pressure difference. As the plunger rises, it makes more space above the water, lowering pressure there. Atmospheric pressure-the push from surrounding air-then drives water up into the pump. Push the plunger down, and a one-way valve lets water move onward while stopping it from slipping back. Lift it again, and another valve opens to admit more water. The exact valve motion depends on the pump's design, but each stroke guides water in one direction. There's a limit: air pressure can lift water only so far. So what makes water rise? The pump lowers pressure above it; air does the pushing.