Artificial Intelligence Generated Content(AIGC)reflects choices made by both users and machines.When choices made by users satisfy the threshold of copyrightability,AIGC should be acknowledged as a work.Decision-makers should focus on human users'contribution rather than machines'contribution,on what human users contribute rather than what they do not,and on the substance rather than the forms of the contribution.Under these guidelines,a significant portion of AIGC is likely to be copyrightable works.The perceived"randomness"of AIGC is confined to areas designated by users,making the content non-random from the user's perspective and not hindering the copyrightability of AIGC in a lump-sum way.Notably,prompts in textual content could potentially be embodied in visual arts.Examining the history of copyright and photography reveals that machine contributions do not necessarily diminish human authorship to the point where users are not eligible to be authors.Recognizing the possibility of AIGC being considered as works aligns with the most cognitively efficient way to balance the interests of creators and users.Copyright law provides sufficient room for the public to act freely,including the rule on independent creation and flexibility on remedies for infringement.