Games that are at least five years old and not sold by companies anymore. They are generaly considered illegal but the copywrite has expired. Sometimes the game company re-issues the game as a classic and then it is not abandonware anymore.
software that the original owner no longer offers to the public. Abandonware refers to a product that is no longer marketed or distributed by the author/company that published it. Orphanware is used when the author cannot be located or the company is no longer in existence. Copyright laws apply to Orphanware and Abandonware. The programs are freeware only if they were released as freeware (or given freeware status by the owner at a later date).
Software that is no longer being offered for distribution by its author. The Copyright to the program is retained by the author.