Sometime you may need to know whether you are running a 32 bit or 64 bit Operating System to choose which version of software to download.
There are prominent 2 ways to find out
if it is a 32bit Ubuntu, the output looks similar to below. Highlighted i686 or i386 identifies OS is 32bit
Linux UbuntuBox 3.19.0-59-generic #66~14.04.1-Ubuntu SMP Fri May 13 17:27:10 UTC 2016 i686 i686 i386 GNU/Linux