01What is the primary difference between a collection returned by `querySelectorAll` and one returned by `getElementsByClassName`?
02Which method is best suited for event delegation to find the nearest ancestor matching a selector?
03What does the `element.matches(selector)` method return?
04To avoid XSS vulnerabilities when inserting user-provided text, which property should you prefer over `innerHTML`?
05What is 'Layout Thrashing' in the context of DOM manipulation?
06Which advanced CSS pseudo-class, supported in modern browsers, allows you to select a parent element based on its descendants?
07When using `querySelectorAll('[data-id^="user-"]')`, what does the `^=` operator signify?
08Which high-performance DOM API allows for efficient, low-level filtering and iteration of the DOM tree without creating intermediate arrays?
09What is the primary benefit of using a `DocumentFragment` when performing batch DOM updates?
10How does the browser's CSS engine typically process complex selectors like `div.container > ul li.active`?