A software license is an agreement made between the user and the software developer that sets up the conditions of use of the software. Proprietary software uses license agreements to protect the copyright nature of the software, and prevent users from making alterations to code, or misusing the software.
- Free Software licenses such as the GNU General Public License are used to guaranteed the continued free and copyright-free nature of a piece of software, and encourages those that use it or change the code to publish their own changes.
- Shareware licenses allow users to test software out for a trial period before paying for the software.
- Software can be free or paid for. Many companies give away crucial software like drivers for free, but charge for applications like sound editors, graphics packages and word processing/database/spreadsheet packages.