回 is a picture of a spiral or whirlpool — water turning back on itself, circling around. A square inside a square captures that 'turning back'. So 回 means to return, to go back, to circle round.
回 is 'to return': 回家 (go home, with 家 — one of the most emotional phrases in Chinese, especially at New Year when hundreds of millions 回家), 回来 (come back, with 来), 回去 (go back, with 去), 回头 (turn one's head / later, with 头). It's also a measure word for times/occasions (一回 = once), and 回 names the Hui people, a Muslim ethnic group. But its heartbeat is 回家 — going home.
A spiral, a square within a square — circling back, to RETURN.
回家 ('go home') drives the largest annual human migration on Earth — China's New Year travel rush (春运), when hundreds of millions return home for the holiday.