Publishing companies put up money to develop books and then sell the book to recoup some of their initial investment. To protect their book from being illegally copied companies copyright the book.
Software companies are no different.
Software companies put up money to develop their software and then try to sell copies of their software to recoup some of their investment and presumably, to make a profit. In the early days of the computer, software piracy was a major problem, however with the development of writable CD-Roms, the problem is even bigger. The copying of illegal software has become a booming industry in many parts of the world and much of the pirated software moves around the world on the Internet. Software piracy costs all of us. More than 600,000 people in the United States are directly employed in the software industry.