1. What is HTML5 and its major features?
  2. What is the <canvas> element?
  3. How does canvas differ from SVG?
  4. What is SVG in HTML?
  5. What is the <picture> element?
  6. How does responsive images work?
  7. What is lazy loading in HTML?
  8. How do you lazy-load images?
  9. What are Web Components?
  10. What is Shadow DOM?
  11. What are custom elements?
  12. What is the <template> tag?
  13. What is microdata in HTML?
  14. How does microdata help SEO?
  15. What is structured data/schema?
  16. How does HTML help SEO?
  17. What are meta tags for SEO?
  18. What is canonical URL?
  19. What is Open Graph metadata?
  20. What is progressive enhancement?
  21. What is graceful degradation?
  22. What is critical rendering path?
  23. What is HTML parsing?
  24. What is DOM rendering?
  25. What is preload and prefetch?
  26. What is the <dialog> element?
  27. How do showModal() and close() work?
  28. What is tabindex advanced usage?
  29. What is ARIA role usage?
  30. What is accessibility best practice?
  31. What is WCAG?
  32. What is server-sent events (SSE)?
  33. What are Web Workers?
  34. What is WebSocket?
  35. What is iframe sandbox?
  36. What are data attributes use cases?
  37. What is drag and drop API?
  38. What is HTML Geolocation API?
  39. What are multimedia formats supported by HTML5?
  40. How do you embed video in HTML5?
  41. How do you embed audio in HTML5?
  42. What is <track> tag?
  43. What is crossorigin attribute?
  44. What is HTML manifest file?
  45. What is PWA (Progressive Web App)?
  46. What is caching in HTML5?
  47. What is service worker (concept)?
  48. What is HTML minification?
  49. How do you optimize HTML performance?
  50. What is SEO-friendly HTML structure?
  51. What are semantic best practices?
  52. What is accessibility testing?
  53. What is cross-browser compatibility?
  54. What are HTML global attributes?
  55. What is difference between display:none and visibility:hidden?
  56. What is hidden attribute?
  57. What is form autofill and autocomplete?
  58. What is novalidate attribute?
  59. What is <output> used for?
  60. What are best practices for clean HTML code?