According to Osho, knowledge is borrowed belief—the accumulated experiences of others stored in the brain; wisdom is your own accumulated experience, nearer but still of the past; understanding is non-accumulative, a present-moment clarity of being. Knowledge and wisdom can be replaced or brainwashed; understanding cannot. If living increases your store, it’s knowledge or wisdom; if living deepens presence, it’s understanding.
Knowledge is what you’re told, wisdom is what life has taught you, and understanding is seeing clearly right now without clinging to the past.