Copyright And Copyleft
Copyright gives the owner of certain types of materials protection over the work and the ways in which it can be used. The general rule is that the author is the first owner of the copyright in a literary, artistic, music or artistic work.
Copyleft has been introduced to make, for example, software free. this means that the software can then be freely distributed and modified without any ramifications. The many positives to this include improvements being able to be made to the software, allowing programmers to contribute to the community of users.