强 has three readings: qiáng (strong, this entry — by far the most common), qiǎng (to force, to compel — see 勉强, 强迫), and jiàng (stubborn — almost exclusively in 倔强). Default to qiáng unless you spot one of those compounds.
usage
In casual speech, 强 means 'impressive / awesome': 你太强了! Common in gaming and internet culture, like English 'OP' or 'beast'.
Bow radical on the left — the indexing semantic. The original meaning was a tough, hard bow, since tension is what makes a bow strong. Strength was conceptualized through weapon-tension. Same radical anchors 弱 weak, 引 to draw, 张 to stretch open.
Right side (口 over 虫) supplies the sound: 虽 drifted to qiáng across millennia of Old Chinese sound shifts. 虽 also depicts a hard-shelled weevil; the tough-insect imagery merged with the bow on the left to give the modern senses 'strong, tough, forceful'.