Answer: It means that whatever was under copyright wasn't violated.
Explanation: The definition of a copyright is: the exclusive legal right given to the originator or an assignee to print, publish, perform, film, or record literary, artistic, or musical material, and to authorize others to do the same. It is a protected source of material.
Your question of "doesn't infringe on copyright " means that the material stayed protected. Not violated in any way.