What is difference between JRE and JDK?

Related questions

1. Can I have two versions of JDK?
2. Can I have multiple versions of Java installed?
3. Can I install multiple JRE versions in my machine?
4. Can I install only JRE in my machine?
5. Can I install same JDK version two times in my machine?
6. Can you downgrade Java?
7. Where is JDK installed in Ubuntu?

Tags

1. #environment
2. #which
3. #jaimin
4. #specification
5. #place
6. #provides
7. #patel
8. #difference
9. #where
10. #programs
11. #machine
12. #abstract
13. #software
14. #between
15. #executed
16. #bytecode
17. #basically
18. #development
19. #runtime
20. #while