The first copyright law we know of was the Statute of Anne, enacted in Great Britain in 1710. "The objective of the statute was to encourage the writing of "useful work" through granting authors the sole right to print their books for 14 years. (Bonner et al, 2). You can check out the full text on Yale Law School's Avalon Project website.

When the United States Constitution was written, the authors - obviously familiar with the Great Britain system of copyright - chose to include the following when enumerating the powers of Congress:

"To promote the Progress of Science and useful Arts, by securing for limited Times to Authors and Inventors the exclusive Right to their respective Writings and Discoveries;" (U.S. Constitution, Article 1, Section 8)

This is the basis for our copyright law today, which lives in Title 17 of the U.S. Code.

Copyright owners maintain the exclusive right to do the following:

• Reproduce the work.  (Make copies. This one has become a huge headache in the digital world...see more here.) 
• Make derivative works. (Build upon the work to create new works...for example, a remix or a mashup.)
• Distribute copies to the public by sale or "other transfer of ownership, or by rental, lease, or lending."  (No one can sell your work...without your permission.)
• Perform the work publicly.  (This includes readings of literary works - only the copyright holder has this right.)
• Display the work publicly.  
• Transmit digitally (in the case of audio transmission of sound recordings)

These rights are exclusive to the copyright holder; no one else has these rights for someone else's content, unless the copyright holder gives them the right.

But wait!  There are limits on these rights, and those limits are the reason we don't have to ask permission every time we do something covered by the above. These limitations protect libraries, schools and content creators by allowing them to do their work, to a point.

Section 108 allows libraries to make copies under certain situations.  Sction 109 or The First Sale Doctrine, limits the copyright owner's control over sale to the first one.  This is how individuals can re-sell or loan physcial copies of their own books or cds without violating copyright.  

What about educational use?  There is in fact, a limit on these rights when the use is in an educational setting, but it's not as limiting as some might like: The exception for educational use, Section 110, ONLY covers the performance and display rights.  The TEACH Act is more comprehensive, but also has limitations.  See the "Share" section for more information.

You may notice that there's a big limit I haven't mentioned yet, and that's Fair Use.  That limitation is so important, it got its own section...let's go!

The Center for Intellectual Property Handbook describes Fair Use in a really elegant way:

"Fair use enables the use of the copyright owner's exclusive rights for activities that serve the common good and foster debate, criticism, education and scholarship."

In other words, the doctrine of fair use allows us to balance the rights of the copyright owner with what society needs.  Asserting that a use is fair allows a user to continue that use without seeking permission.  However, that assertion must be based on reasonable belief, and involves weighing four factors:

• the purpose and character of the use, including whether such use is of a commercial nature or is for nonprofit educational purposes;
• the nature of the copyrighted work;
• the amount and substantiality of the portion used in relation to the copyrighted work as a whole; and
• the effect of the use upon the potential market for or value of the copyrighted work

It is important to note, however, there is no magic number.  Whether or not a use is fair is determined when a copyright owner sues a content creator, and the content creator defends him or herself by saying, "hey, wait, that's fair use!"  The courts have handed down several decisions which give users guidance in this area.  For details, see the Legal Background section.

For more information on how to evaluate if a use is fair, see the "Create" tab and "Fight for Your Right to Fair Use."