The U.S. Constitution authorizes the federal government to grant copyright protection to original works of authorship. Copyright protection grants you a legal monopoly over certain uses of your work for the duration of the copyright. You don't have to be a U.S. citizen or resident to take advantage of federal copyright protection.
Unlike patents, which protect ideas themselves, copyrights only protect expressions of ideas. All you need for copyright protection is to create an original work of authorship in a tangible form, such as a recording or a manuscript. You don't need to place a copyright symbol on your work. Copyright law prevents anyone but you and those you authorize from publicly performing, displaying, reproducing, distributing, or selling your work. It also prevents others from creating derivative works — by using a cartoon character you created, for example, in another comic strip.
Copyright law attempts to strike a balance between providing authors with an incentive to create works, and providing the public with the benefits of the free flow of information. To protect the free flow of information, copyright law carves out three major exceptions to copyright protection. The "fair use" exception allows you to use small portions of copyrighted works under certain circumstances. The "first sale" exception allows you to sell second-hand copies of someone else's work (this exception doesn't apply to digital copies). The "work for hire" exception allows you to sell your copyright to your employer as soon as it is created — by developing an algorithm for a software company, for example.
Complex rules apply to the duration of copyright protection. These rules depend on many factors, such as when the work was created and who the original copyright holder was. In general, however, if you owned the copyright when the work was created, it lasts until 70 years after your author's death, no matter who owns the copyright at that time. If you created the work as a work for hire, it lasts until 120 years after its creation or 95 years after its first publication, whichever first occurs.
You can register your work on the website of the U.S. Copyright Office or through an online service provider such as LegalZoom. All you need to do is to fill out an application, upload a digital copy of your work, and pay a small fee for each work. You don't have to register your work with the U.S. Copyright Office to obtain copyright protection. If someone infringes your unregistered work, you can register it after infringement and then file a lawsuit.
Copyright infringement lawsuits must be filed in federal court. As long as you registered your work either before the act of infringement occurred or within three months of its first publication, you can claim statutory damages and attorney's fees. The advantage of statutory damages is that you can claim up to $150,000 per act of infringement without having to prove that you suffered any damages. If you are not eligible for statutory damages and attorney's fees, you can still claim the amount of damages you can prove. Other possible remedies include seizure of illegal copies and an injunction against further infringement.