For an aeroplane to get in the air, it needs to create a lift force which is greater than the weight. This upwards force comes from the wings, which create lift using a formula.Gravity pulls downwards on a plane with a force equal to its weight (gravity doesn’t know or care if it the plane is in the air or on the ground, it pulls the same!).
For a plane to take off, the wings must push upwards more than gravity pulls downwards. A big plane (like a 747 or 777) weighs about 200 tonnes. That means the wings must push upwards more than 200 tonnes!
Even though the plane is heavy the force of the air is very strong. An aeroplane stays up when the force of the air pushes up harder than the force of the weight pulls the aeroplane down.
In simple terms you can say that the air flows around the plane because of the upward curving wings the air above flows past faster then below.
When an aircraft moves into the wind, the wings cut the airflow in half. Some air travels above the wing, some air travels below the wing