Why do Harriers take off and land vertically?

The Harrier was the first jet aircraft in the world to achieve vertical takeoff and landing. Its engine is different from normal jet

aircraft in that it is capable of generating thrust in 2 directions, vertically upward and horizontally forward.

In appearance, its engine resembles a set of pants, with 2 nozzles at the front and back, and these 4 nozzles can rotate at the same

time. When the plane takes off, the 4 nozzles deflect downward at the same time until they are completely perpendicular to the ground, and the engine

generates thrust through the vertical nozzles like 4 invisible pillars to lift the plane. Once the plane is in the air, the pilot

gradually maneuvers the nozzles backward, which generates a horizontal thrust, and the weight of the plane is supported by the lift generated by the

wings, and the thrust generated by the engine pushes the plane forward. When the plane lands, when the nozzle is

completely perpendicular to the ground, because the plane is hovering in the air, there is no forward momentum, and the lift on the wings disappears, and the weight of the plane is again supported entirely by the vertical thrust generated by the engine. Then the pilot began to

close the throttle, reducing the amount of fuel supplied by the engine, the vertical thrust gradually became smaller, and the aircraft began to descend slowly until

finally landing. As a result, the Harrier's entire takeoff and landing process could be accomplished with only a single piece of open space, ending the history of

jet airplanes that had to rely on runways for takeoffs and landings.