开关
kāi guān · HSK 6
switch
🔛 kai (open) + guan (close) = the open-close thing, a switch
A switch toggles between two states: kai means open/on, guan means close/off. Together they form the word for any on-off switch or toggle.
开 — two hands 廾 + door 门 (open gate)
Originally written 開, showing two hands (廾) lifting the bar (一) off a gate (門) to open it. The simplified form 开 keeps the two-hands element and drops the gate. Core meaning 'to open' extended to 'start, operate, bloom'.
关 — door 门 + simplified 关 inside
关 is the simplified form of 關. The traditional character showed a gate (門) with a bolt or crossbar inside, depicting a barred door — hence 'to close' or 'shut'. Meaning later extended to 'pass' (a guarded gate), 'barrier', and figuratively 'concern' or 'connection'.