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

Dec 19, 2018, 13:00 (1 Talkback[s])
(Other stories by Anonymous)

I need to find out if my Linux server is running on 32-bit or 64-bit system. How do I know if my Linux is 32 bit or 64 bit? How do I find out the CPU architecture on Linux and running kernel?