対照
たいしょう · taishou · JLPT N3 · noun
comparison
☀️🌙 対 opposite + 照 shine on = items set facing each other so each lights the other
対 (tai) means facing or opposite, as in 反対 opposition. 照 (shou) means to shine light on, as in 照明 lighting. Put two things face to face so each one shows up the other's differences, and you have a contrast.
照 — 昭 (bright) phonetic + 灬 (fire radical)
照 is a semantic-phonetic compound. The bottom 灬 is a variant of 火 'fire', giving the meaning of light or illumination, while 昭 'bright' on top supplies the sound 'zhào' and reinforces the brightness sense. It originally meant to shine light on something, later extending to 'reflect', 'photograph', and 'according to'.