Questions about copyright law from a designers point of view. Answers should not be treated as bona fide legal advice, but instead as advice from designers who've experienced copyright issues in their career. Ask anything about how copyright relates to graphic design, though bear in mind that we are not lawyers.
Copyright is a legal concept, enacted by most governments, giving the creator of an original work exclusive rights to it, usually for a limited time, with the intention of enabling the creator of intellectual wealth (e.g. the photographer of a photograph or the author of a book) to get compensated for their work and be able to financially support themselves.
Generally, it is "the right to copy", but also gives the copyright holder the right to be credited for the work, to determine who may adapt the work to other forms, who may perform the work, who may financially benefit from it, and other related rights. It is a form of intellectual property (like the patent, the trademark, and the trade secret) applicable to any expressible form of an idea or information that is substantive and discrete.