Which is better px or em?

Related questions

1. What is the use of EM in CSS?
2. What is an em?
3. Should I use em for padding?
4. What is the difference between PX and REM?
5. What is EM in CSS style?
6. What Is REM bootstrap 4?
7. What is PX photo?
8. What is the new in bootstrap 4?
9. What Is REM and EM in CSS?
10. What is difference between REM and PX?

Tags

1. #fixed
2. #equal
3. #computer
4. #instance
5. #pixels
6. #current
7. #scalable
8. #units
9. #media
10. #document
11. #screen