Browser bank Platform APIs & Isolation Browser / 6 questions Your progress 0 / 6 done Saved in this browser. Reset All 6 Medium 5 Hard 1 Hide done No questions match those filters. 1 What is the same-origin policy, and what counts as a different origin? Medium 2 How does CORS work, and what's the role of a preflight `OPTIONS` request? Medium 3 What are Web Workers, and what can and can't they do compared to the main thread? Medium 4 What can a service worker do that a web worker can't, and what's its lifecycle? Hard 5 How does `postMessage` enable cross-context communication safely? Medium 6 What is the History API, and how do SPAs use `pushState` for client-side routing? Medium ← Previous Storage & Cookies