According to 17 U.S.C. §106, the owner (or holder) of a copyright has six exclusive rights:
1. The right to reproduce the copyrighted work
2. The right to prepare derivative works based upon the work
3. The right to distribute copies of the work to the public
4. The right to perform the copyrighted work publicly
5. The right to display the copyrighted work publicly
6. The right to perform the copyrighted work publicly by means of a digital audio transmission (in the case of sound recordings)
The right of reproduction grants the copyright owner the right to exclude others from reproducing (for example, photocopying) the copyright protected work, while the right to prepare derivative works gives the copyright owner the right to exclude others from creating works based on the protected work. (Examples of derivative works include translations, arrangements, abridgements, and condensations.)
The right of distribution gives the copyright owner the exclusive right to distribute their work to the public by sale, rent, lease, or lending. However, there is an exception to the right of distribution called the first sale doctrine: after the first sale or distribution of the work, the copyright owner no longer has the distribution right. It works like this: I write a book, and copyright in the book attaches from the time I first put the book in a tangible medium of expression. I hold the right of distribution and can forbid others from distributing it without my permission. But if I sell the book, I lose my distribution right. After a book has been purchased (the first sale of a copy), “the copyright holder has no say over how that copy is further distributed. Thus, the book could be rented or resold without permission of the copyright holder." (By the way, the first sale doctrine is the legal basis by which libraries can loan books to library users without permission of the copyright owner.)
The fourth right, the right of performance, gives the copyright owner the right to exclude or control all others from publicly performing the work without the permission of the copyright owner, although there are numerous exceptions. The fifth right, the public display right, is similar in a lot of ways to the right of performance; however, the first sale rule of 17 U.S.C. 109(c) allows for the public display of a lawfully-acquired copy of a copyrighted work by the owner of the copy, even though the owner of the copyright is a different entity. As a result, a museum can lawfully display a painting that the museum owns, as long as the painting was lawfully acquired. [See Mary LaFrance, Copyright Law in a Nutshell (St Paul: Thomson/West, 2008), 216.]
Copyright infringement occurs whenever someone exercises one of these exclusive rights of the copyright owner without the copyright owner's permission (assuming the work is still under copyright protection), although there are several exceptions that allow copyrighted materials to be used without permission from the copyright owner, such as the fair use exception. However, if you want to use a copyright-protected work, and you cannot obtain permission (and your use does not fit within an exception such as fair use), then do not use the work. Otherwise, you will be infringing. And infringement does not have to be intentional.