With a Creative Commons license, you keep your copyright but allow people to copy and distribute your work provided they give you credit — and only on the conditions you specify.
PUBLIC DOMAIN
Public domain software is software that has been placed in the public domain, in other words there is absolutely no ownership (such as copyright) of the "intellectual property" that the software represents.
FREEWARE
The only criterion for being classified as freeware is that the software must be fully functional for an unlimited time with no cost, monetary or otherwise. The software license may impose restrictions on the type of use including personal use, individual use, non-profit use, non-commercial use, academic use, commercial use or any combination of these. For instance, the license may be "free for personal, non-commercial use".
SHAREWARE
The term shareware, refers to copyrighted commercial software that is distributed without payment on a trial basis and is often limited by any combination of functionality, availability or convenience. Shareware is often offered as a download from an Internetwebsite or as a compact disc included with a periodical such as a newspaper or magazine. The aim of shareware is to give buyers the opportunity to use the program and judge its usefulness before purchasing a license for the full version of the software.
FREE SOFTWARE LICENCE
A free software licence is a software licence which grants recipients rights to modify and redistribute the software which would otherwise be prohibited by copyright law. A free software licence grants, to the recipients, freedoms in the form of permissions to modify or distribute copyrighted work.