Where the name comes from. In French, this kind of chart is called a camembert, not a sunburst. A wheel sliced into wedges, like the cheese. The name wrote itself.
Rings work outward from the center: the inner ring is the folder you scanned, the next ring its sub-folders, and so on. A big wedge is a big folder, so the things worth your attention are simply the widest slices.
Getting around
- Click a wedge to drill into that folder. The chart redraws with that folder at the center.
- Click the center to go back up one level.
- Use the breadcrumb at the top to jump to any parent folder, the same way you would in Explorer.
- Right-click a wedge to reveal the folder in Explorer or send it to the Recycle Bin.
The Top items panel lists the largest things inside whatever folder you are looking at, with sizes, so you can read the same information as a plain list. Search is scoped to the folder in view, so drilling in narrows what you search.
The little red-to-green bar you see around the app is a free-space gauge. It shows how full a drive is at a glance, and moves as you clear things out.