Free software is generally free or, depending on the owner, has a small distribution cost. Free software is software that a user can use, modify and distribute without the need to purchase the product or pay for any kind of software license.
Although free software can be distributed free of charge, it should not be confused with freeware, which by definition does not require payment for use. Some programs distributed under the criteria of free software do not include the source code, only the executable program, therefore they are not considered free software but free applications.
A program is considered free software if users can do the following:
- Use the program, for any purpose.
- Change the source code to fit your needs.
- Redistribute copies so you can help your neighbor.
- Distribute copies of software to third parties.
Free software may be distributed under one of the following licenses:
- Public domain software – no copyright protection, may be freely incorporated into any work, whether proprietary or free.
- Permissive licenses, also called BSD licenses. These licenses are also known as copyfree since they have no restrictions on distribution. The author retains copyright and permits modification and redistribution.
- Copyleft licenses, with the GNU General Public License being the most prominent. The author retains the copyright and permits redistribution under the restriction that all redistributions are included under the same license. They are also known as viral license.