How do I know if my OS is 32 or 64 bit Linux?

Related questions

1. Is Debian Testing stable enough?
2. What is the difference between Debian and Ubuntu?
3. Is Linux the same as Unix?
4. Can I get Red Hat for free?
5. What is Debian testing?
6. Is Debian unstable safe?
7. Why Red Hat is used?
8. Is Debian same as Ubuntu?
9. Is Arch Linux free?
10. Is Kali a Debian?

Tags

1. #hardware
2. #command
3. #press
4. #running
5. #uname
6. #system
7. #shows
8. #displays
9. #enter
10. #whether
11. #machine