What is the difference in HTML 4 and HTML 5?

Answer:
Unlike HTML 4 you cannot do these things in HTML 5:
- using attributes without double-quotation like <font face=tahoma> instead of <font face="tahoma">
- Closing tags wrong <b><i>test</b></i> instead of <b><i>test</i></b>
- Special Tags Closing <br> instead of <br />
First answer by Pezhvak. Last edit by Pezhvak. Contributor trust: 2 [recommend contributor recommended]. Question popularity: 2 [recommend question].