Four contexts, four different sets of powers. Click a context to see what it can and can't touch, then play the data-flow.
| Capability | Popup | Content | Worker | Options |
|---|---|---|---|---|
| Access page DOM | ✗ | ✓ | ✗ | ✗ |
| Own DOM / HTML UI | ✓ | ± | ✗ | ✓ |
| Full chrome.* APIs | ✓ | limited | ✓ | ✓ |
| Always available | ✗ | per-page | on events | ✗ |
| Long-lived state | ✗ | ✗ | ✗ | ✗ |
No context keeps long-lived state — persist with chrome.storage (Part 7).
The popup asks the worker to do something on the page.