Why is the focus of the collecting lens called real, and the scattering one – imaginary?

Beams parallel to the main optical axis, after refraction in a converging lens, intersect at the main focus. In the diffusing lens, the extensions of the refracted rays intersect at the main focus.

Remember: The process of learning a person lasts a lifetime. The value of the same knowledge for different people may be different, it is determined by their individual characteristics and needs. Therefore, knowledge is always needed at any age and position.