Confused with Atomic Mass

[my_books]

Which one is correct and why ?

https://en.wikipedia.org/wiki/Atomic_mass

or

https://chemistry.about.com/od/chemistryglossary/a/atomicmassdef.htm

 

[sreevyas]

This link explains the atomic mass unit, which is the carbon atom as reference

https://chemistry.about.com/od/chemistryglossary/a/atomicmassdef.htm .
don't confuce with atomic mass unit, Atomic number and atomic mass
three are different

__sree