HTML5 is the more advanced version of HTML4.So it has many features and advantages than HTML4.Many people thinks HTML4 is bit complicated,but HTML5 offers more flexibility to developers. HTML5 comes with new tags, new features, and has simplified various functions over HTML4.
HTML5 improvements over HTML4:
1. Simplified syntax
2. Mobile-friendliness
3. Better performance
4. Accessibility
5. Future-proof
6: Error handling(forgiving some minor syntax errors)