The term “flight” can mean quite a few things due to the number of definitions that it has. Mostly, flight refers to the procedure of moving through the air and the thing does not reach the ground. When analyzing the physics of flight, there are four types of forces regarding to flight. Thrust refers to being pushed into the forward position. Lift refers to movement or force in the opposite direction of flow.
Drag is the force coming from the opposite direction and weight is due to the force of gravity pushed upon an object. To visualize these terms, you can view them surrounding an airplane. Lift would be on top of the plane. Weight would be below the plane. Thrust is to the left of the plane and drag would be to the right of the plane if the plane is facing left.