What is "copyright" when looked at as a concept, beyond the rules created by nations?

The underlying philosophy of copyright is that the creator of a work should have the exclusive right to control the use of that work and to profit from that work for some period of time - or "sell" that right to someone else.  One "owns" what one creates - and part of that ownership is the ability to exclude others to use it, or to delegate ones' interest to another.

By securing for limited times to authors the exclusive right to their writings, copyright in the United States is meant to promote the progress of science and the useful arts.  -- U.S. Constitution, Article I, Section 8. In Great Britain, copyright was originally intended "for the encouragement of learning, by vesting the copies of printed books in the authors or purchasers of such copies."  -- Statute of Anne, title. The basic idea is that governments want to encourage writers to write, and they do so by giving them a property interest in the things that they write.  As stated by other answers, this property right is generally granted for a limited time to balance the interest in incentivizing authors with the interest in having a common that is freely available for all to use. Such a granting of a property interest can be justified by the Lockean theory of property, which basically states that an individual owns his own labor, and so by creating something from the common, the property right over the individual's labor extends to what the individual created.  See http://www.lonang.com/exlibris/locke/loc-205.htm, section 27, which I'll quote in full, because I think it's interesting (emphasis mine): He that is nourished by the acorns he picked up under an oak, or the apples he gathered from the trees in the wood, has certainly appropriated them to himself. Nobody can deny but the nourishment is his. I ask, then, when did they begin to be his? when he digested? or when he ate? or when he boiled? or when he brought them home? or when he picked them up? And it is plain, if the first gathering made them not his, nothing else could. That labour put a distinction between them and common. That added something to them more than Nature, the common mother of all, had done, and so they became his private right. And will any one say he had no right to those acorns or apples he thus appropriated because he had not the consent of all mankind to make them his? Was it a robbery thus to assume to himself what belonged to all in common? If such a consent as that was necessary, man had starved, notwithstanding the plenty God had given him. We see in commons, which remain so by compact, that it is the taking any part of what is common, and removing it out of the state Nature leaves it in, which begins the property, without which the common is of no use. And the taking of this or that part does not depend on the express consent of all the commoners. Thus, the grass my horse has bit, the turfs my servant has cut, and the ore I have digged in any place, where I have a right to them in common with others, become my property without the assignation or consent of anybody. The labour that was mine, removing them out of that common state they were in, hath fixed my property in them. Finally, to state that copyright is "a concept applied to abstract ideas and information" as suggested in the question is demonstrably false, at least in the US.  Copyright protection in the US is applied to "original works of authorship fixed in any tangible medium of expression, now known or later developed, from which they can be perceived, reproduced, or otherwise communicated, either directly or with the aid of a machine or device."  17 U.S.C. 102(a).  "In no case does copyright protection for an original work of authorship extend to any idea, procedure, process, system, method of operation, concept, principle, or discovery, regardless of the form in which it is described, explained, illustrated, or embodied in such work."  17 U.S.C. 102(b).This answer is not a substitute for professional legal advice....

Is copyright applied to "information" or "works"? What can possibly an "original work of authorship" be if not information, organized in shape by ideas, sometimes deductive or inductive, but very often completely ad-hoc. It is without a doubt reasonable to consider a work of authorship as information which has been coded. Is there a "copyright concept"? The mere existence of different form of "copyright", applied differently in different countries, justifies a concept of copyright. There are even rules of integrating different implementations of this concept through the Bern convention. Even with these conventions there is a constant pressure by different lobby groups to adopt new ideas on what "protection of works" and "right to copy" means. Can code fixed in a tangible media ever be considered as an abstract idea? This is perhaps a too wide generalization from my part, but  I would say that even in the US this might be possible because of how copyright is formulated: Copyright protects works which "can be perceived, reproduced, or otherwise communicated, either directly or with the aid of a machine or device". The "can be perceived" and "can be reproduced" parts presents some serious complications, especially when combined together. To explore this idea consider when the copying of a code containing an image of Mickey Mouse (the idea), isn't a copyright infringement. Who would dare to go up against Disney to prove it? Would changing colors help? Would chaining animation pattern help? Would changing the proportions of the chartoon mouse help? Would chaining voice help? In most cases no, because copyright, in practice does indeed extend into an abstract and must so or it would trivially be worked around. The way copyright if formulated it means that any sub-part of the whole is protected. This is why people get convicted for downloading files using torrents or even get convicted for helping people downloading sub-parts of a work. The obvious problems comes when we realize that all code when reduced to sub-parts is linked together and we copy these parts between us all the time or communication wouldn't occur. As stated by 17 U.S.C. 102(a)., an algorithm for putting together arbitrary code segments into a whole can't be responsible for copyright infringement. Or is a book describing how to draw mickey mouse infringing on mickey mouse copyright if it describes in detail how to do it? I guess the obvious contradictions in US laws comes from the fact that the law mostly stems from rhetoric reasoning rather than a profound understand of the nature of information.