Answer
Reflow recalculates element sizes and positions; repaint redraws their appearance. • Changing width may cause reflow and repaint. • Changing only color usually needs repaint but not reflow. • Too many repeated changes can make animation feel slow.
💡 Simple Example
<p>Changing a box from `width: 100px` to `200px` can move nearby content.</p>
⚡ Quick Revision
Reflow changes layout; repaint redraws appearance.