Collision coalescence.
Rain is formed by the collision & joining of small & large water droplets held in suspense.
When they get big enough they are dropped by gravity & ripped apart by air friction forming rain.
Bergeron Findeisen states that water droplets (supercooled) and ice crystals coexist together in a high convectional cloud such as cumulonimbus.
High vapour pressure exists on the ice crystals than supercooled water droplets. The droplets migrate and are deposited on the ice crystals making them large.
They fall down and melt along the way as they encounter warm air forming rain droplets.
https://thegeoroom.co.zw/climatology/rainfall-formation-theories/
Sorry.
High vapour pressure actually exist on Supercooled droplets & low along ice crystals.
Don't make a mistake there