Why did I receive 2 differnt code numbers for my microsoft and outlook accounts?

I updated the security in my Microsoft account.  The first time I was directed to Outlook and  I promptly received  a code by phone.

  Then I signed in again and  was asked again for a phone number for my Microsoft account.  I entered my phone number and  I  promptly received a DIFFERENT code . 

    Does Outlook,  Skydrive etc. all have different code numbers???