Generic drugs contain the identical chemical copy of their cognate originator drug’s active ingredient and this can be proven by their physicochemical properties and the structural identity. A more complex situation is given when it comes to biological drugs, where identical copies cannot be produced. Hence, similar to the approval of the originator biological drug, great care must be employed when approving biosimilar protein drugs. Furthermore, this needs to be continued after the entrance of biological/biosmilar drugs into the market: rigorous pharmacovigilance during their application is the key and the close surveillance of their production is mandatory. In this review, we will highlight the differences between generic and biosimilar drugs and point out what healthcare professionals need to know.