Why does the air pressure in the straw decrease when absorbing water with a straw?

Now put a straw into the water, the inside of the tube is also atmospheric pressure, the liquid level in the tube is on the same plane as the water level in the basin outside the tube, but the air pressure in the straw is lower than a large vapor pressure, and the water level in the basin is still atmospheric pressure. At this time, the water pressure inside and outside the pipe is different, so liquid water must transfer this force and find its own balance, so the atmospheric pressure on the water surface outside the pipe passes through the nozzle to raise the water pressure inside the pipe.