半 is built from the ⺍ (small (top)) and 干 components.
It belongs to a phonetic family with 判, 伴, and 畔 — they share the 半 component and the reading ハン.
A common word using 半 is 半分 (はんぶん), meaning “half”.
Kanji that look similar include 光, 当, 労, and 肖.