The character 回 (huí): to return

A river seen from above, the water a clear turquoise and blue: at the left a wide whirlpool whose rings of white foam spiral in toward a dark blue centre, with one small yellow leaf carried on it. Pale boulders and a few blades of grass fill the lower right, bamboo leaves the upper right. Over the water at the right the character 回 in deep brown, a small empty square set inside a larger square and touching it nowhere.

Pronunciation: huí
Strokes: 6
Level: HSK 1
Radical: 囗
Made of: 囗口

What it means

variant of 迴|回[hui2]

Where its shape comes from

This is not a frame inside a frame. Xu Shen glosses it as "to turn" and remarks that the part in the middle "pictures the shape of what turns": the oldest tracings draw a spiral, a whirl coiled upon itself. Regularisation straightened that spiral into two nested squares, in the same way that it made a rectangle of the mouth and a square of the sun, a brush being no good at circles. The whirlpool in water is now written 洄 huí.

Source: Xu Shen, Shuowen Jiezi (121 CE); the Chinese University of Hong Kong character database.

A way to remember it

A small square set in the middle of a large one, touching it nowhere: the gap all the way round is part of the drawing, as it is in 问. And the bottom of the big square is written last, after the small one, the rule you met in 因 and in 国.

This is a memory aid, not the origin of the character.

Words it appears in

回答 huí dá · HSK 3 to reply; to answer; reply; answer
回忆 huí yì · HSK 4 to recall; memories; CL:個|个[ge4]
回报 huí bào · HSK 6 (in) return; reciprocation; payback; retaliation; to report back; to reciprocate
回顾 huí gù · HSK 6 to look back; to review
回收 huí shōu · HSK 6 to recycle; to reclaim; to retrieve; to recover; to recall (a defective product)
回避 huí bì · HSK 6 to shun; to avoid (sb); to skirt; to evade (an issue); to step back; to withdraw; to recuse (a judge etc)

Writing it

See the stroke order of 回, animated stroke by stroke.