住 = 亻(person) + 主. 主 (zhǔ) means 'master / host' and lends the sound; a person settled in their own place, as its master, is 'to reside'. The person radical confirms it's about a human staying put.
住 means to live (somewhere), reside, stay: 你住在哪里? (Where do you live?), 我住在中国 (I live in China — pairing with 在, which you know). It also attaches to verbs to mean 'hold firm / stop': 站住! (Stop! / Halt! — 'stand-firm'), 记住 (remember firmly, 'record-fast'). A character about staying — in place, or in memory.
A person (亻) settled as master (主) of a place — to RESIDE.
住 also means 'hold firm': 记住 (remember it firmly), 站住 (halt!, 'stand-fast'), 拿住 (grip tight). Stuck after a verb, 住 means 'and stay that way'.