WHOLE CHARACTER
节jié, jiē
joint; knot; section; festival; holiday; a solar term (节气); to economize; to restrain
节 means a joint or section, like 关节 'joint'. It also marks time — 春节 'Spring Festival', 节日 'holiday' — and saving: 节约 'to economize'.
ZDIC: 形声 (the old form 節: 从竹、即声 per the detailed source). The simplified 节 keeps a plant-style crown over a small written piece; the old pieces are not fully visible.
TOP: THE PLANT CROWN — THE WRITTEN REMNANT OF THE OLD BAMBOO SIDE 竹 (ZDIC: 从竹)
艹cǎo
plants; grass (from 草)
Plant-related meaning clue.
In 节: top: the plant crown — the written remnant of the old bamboo side 竹 (ZDIC: 从竹) Shown with its documented or clearly limited role.
BOTTOM: THE WRITTEN LOWER PIECE
卩jié
a seal; the kneeling-figure form
A bound piece; in 爷 it is the reduced remnant after simplification.
In 节: bottom: the written lower piece The old sound side 即 (jí) is not visible in the simplified shape; jié shares only the j- initial and tone 2 with jí — the finals differ. Shown as a written piece.