Rotation and flipping rearrange pixel orientation. A 90- or 270-degree turn swaps width and height, horizontal flip creates a mirror image, and vertical flip reverses top and bottom. These operations correct camera orientation, scanned pages, and asset direction.
The tool renders a new file from the actual pixels rather than only changing an EXIF orientation tag, so the export should remain correct in applications that ignore metadata. JPG output is recompressed, while PNG is preferable for transparency or sharp line work.