Receiving credit by way of acknowledgment rather than authorship indicates that the person or organization did not have a direct hand in producing the work in question, but may have contributed funding, criticism, or encouragement to the author(s).
Some acknowledgments of financial support, on the other hand, may simply be legal formalities imposed by the granting institution.
In film, video, television, theater, etc., credits means the list of actors and behind-the-scenes staff who contributed to the production.
[7] In non-fiction writing, especially academic works, it is generally considered important to give credit to sources of information and ideas.
All of this is thought to improve integrity of the instructional capital conveyed, which may be quite fragile, and easy to misinterpret or to misapply.