Under current US copyright laws, any creative work is automatically protected from the moment it is first published, performed, or produced. This means the creator of the work must be recognized as the legal owner when it comes to fair use of that work by others. Essentially, the writer of a novel or the sculptor of a statue holds all of the legal rights to that work unless or until he or she decides to grant some of those rights to others. One common way to establish these rights is to include the phrase all rights reserved somewhere on the work itself. It is quite common for movie producers to include the phrase as part of the film's closing credits, for example, and publishers may also include it on one of the front pages of a novel. The phrase serves to remind others that the original creator of the work still owns every right to the material.
Some of the rights reserved by the copyright owner include the right to reproduce the work, license the use of the material by others, and create derivative works. "Derivative works" would include creating a motion picture based on a novel or composing a song based on a published poem. The original creator reserves the right to do all of these things and more, but in reality, he or she is more likely to grant others specific rights to the material. The publisher of a well-known rock song, for example, could grant a commercial producer the right to use the song in an advertisement. A painter could also grant reproduction rights to a designated printing company in order to produce posters.
The phrase all rights reserved does not have to appear at all on a published work in order for the creator to receive copyright protection. Many artists and producers use it as more of a warning to those who may be considering unauthorized use of that material or creation. By pointing out that all rights are still held or reserved by the original creator, the phrase establishes awareness of the current copyright laws and an implied willingness to pursue legal action if those rights are violated. This would be the equivalent of a restaurant owner creating a sign establishing his or her right to refuse service to anyone. The phrase doesn't necessarily mean the work could never be used by others for legitimate or artistic purposes, but it does mean the copyright owner must provide written consent before the work can be used legally.