There have been several discussions taking place on other threads regarding the application and implications of copyright. This thread is to be the venue for further discussion of the topic.
Trademark and Patent law are similar and yet distinct from copyright law. They often work in combination with copyright law to offer a more complete protection for the creator. We can discuss those here as well.
Copyright is a property right created by law. The purpose of copyright is to grant to the creator of an original work exclusive rights to its use and distribution with the intention of enabling them to receive compensation for their intellectual effort. As soon as a work is written or recorded on some physical medium its author/artist is automatically entitled to all copyrights in the work unless and until the author/artist explicitly disclaims them, or until the copyright expires.
Copyright laws vary between countries, however many countries are signatory to reciprocal agreements that honor the copyrights of the other signatories to those agreements. Most countries laws contain the same basic elements with the greatest difference being the length of copyright protection. There are other limitations involved depending upon the countries involved.
The holder of a copyright (with rare exceptions) obtains exclusive rights to produce copies or reproductions of the work and to sell those copies; to import or export the work; to create derivative works; to perform or display the work publicly; to sell or cede these rights to others; to transmit or display the work.
Copyright is usually a civil issue though there are some criminal penalties depending upon jurisdiction and level of infringement. That means that the creator must protect his copyright against infringement by bringing suit and proving the copyright. Copyright protects only the original expression of ideas and not the ideas themselves.
There are exceptions to copyright law. They include:
The First Sale Doctrine (Exhaustion Doctrine) - Basically the creator has the right of first sale of the intellectual property. Once sold, the purchaser has the right to resell the property. The first sale doctrine does not transfer the other rights of the creator.
Market Limitations - There are laws that restrict monopolies, encourage competition, limit discrimination, etc., that affect copyright.
Legal Limitations - There are various legal limitations on copyright depending on the country involved.
Fair Use / Fair Dealing - Basically fair use entails using the copyrighted material for other than commercial gain. It also means that the use does not harm the creator's copyright. A reviewer can sample a work even though they get paid to do so. Parody is also generally allowed.
Embodied in Section 107 of the 1976 Copyright Act are four elements courts must consider when determining whether fair use is an adequate and applicable defense: (1) the purpose and character of the work (i.e. the extent to which the work is transformative, not merely derivative of a earlier work), (2) the nature of the copyrighted work, (3) the amount and substantiality of the portion used in relation to the copyrighted work as a whole, and (4) the effect of the use upon the potential market for or value of the copyrighted work.
Accessibility: There are exceptions for accessibility for handicapped persons.