1, all parallel light will converge to a point through the convex lens, and this point is on the focal plane, which is the plane whose focus is perpendicular to the axis of the convex lens, but after the convergence point, the light will continue to move forward and become divergent.

2. Divergent light from the focal point of the lens becomes parallel light after passing through the lens. If the luminous point is in the focus, it still diverges after passing through the lens, but the divergence angle becomes smaller. If the luminous point is out of focus, it will converge after passing through the lens, but the convergence point is out of focus.

If you don't understand, I'll draw you a picture later.

The light in the above picture is transmitted from left to right.