Beams amount per digital beamforming and analog beamforming

Hello experts ,

  1. In analog beamforming we use just 1 beam and in digital beamforming we have multiple beams?
    is there is a rule between number of beams that we use to the type of beamforming (digital or analog)?

  2. About Hybrid beamforming, why we need it in 5g? any specific real scenarios(example/use cases) that hybrid beamforming could help?

  3. Second question about beams , spec standards defined that we can have maximum 4 beams in low bands … so we can’t use 5 beams or 6 beams in low band? what would happen if we use in low band more than 4 beams? would the system work ? what limitation should I take into account if I use more than 4 beams in lowbands?

Appreciated.