而 is a beard — chin line on top, whiskers hanging below. Borrowed early for a grammar word (the beard meaning moved elsewhere), it became classical Chinese's great connective: and, yet, then, but.
而且 'moreover', 而是 'but rather' (不是A而是B: not A but B). Classical texts run on 而 — Confucius's opening line 学而时习之 'to learn and practice in season' hangs on it. Written Chinese still reaches for 而 whenever two clauses need an elegant hinge.
A wise BEARD connecting thoughts — AND YET, BUT RATHER.
The Analects uses 而 over 340 times in a very short book — grammatically it's the duct tape of classical Chinese.