Why Do sessions expire?

Related questions

1. How long do session variables last?
2. How long should a session timeout be?
3. How is session stored in client?
4. What is session management in Django?
5. How are sessions handled in servlets?
6. How are sessions maintained?
7. How session variables are stored?
8. Where is session value stored PHP?
9. How is session data stored?
10. Where are browser sessions stored?

Tags

1. #causes
2. #expired
3. #session
4. #error
5. #cookies
6. #database
7. #enabled
8. #browser
9. #secured
10. #internet
11. #driven
12. #login
13. #sessions
14. #requires
15. #website
16. #browsing
17. #anonymously