The copyright for the software is owned by the author. Each program is accompanied by a file that explains how to register. Freeware refers to programs that require no registration fee. These programs come with no technical support. If the program does not work on your system, you're on your own.
Some freeware programs are also what is called public domain software.
This means that the author has released the copyright and that anyone may use the software for any purpose. Most freeware, however, is not in the public domain. The shareware on the IDG Books Web site is copyrighted by the various shareware authors. You may download any of the software to your computer. You may share it with friends, as long as you distribute it exactly as you received it, including all files that came with it.