A protein is said to be a unit made of amino acids joined to each other by a peptide bond.
Between reading stored information & actual protein there are several steps.
There could be protein-to-protein variations when there are a few changes when proteins are produced.
Such steps are the reading of information & synthesis into the mRNA, the reading of mRNA & the synthesis of the amino acid chain, and its eventual folding into the mature protein.
As a result, not every protein is essentially seen as the same, although it is composed of the same codons.