Free software is often referred to as open-source software, which means that users have the right to access, modify, and distribute the software for free. Other synonyms for free software include freeware, which refers to software that is available for free but may have limited features or functionality, and shareware, which allows users to try the software for a limited period before purchasing a license. Another synonym for free software is libre software, which emphasizes the user's freedom to use, study, modify, and distribute the software. Regardless of the term used, free software provides an important alternative to proprietary software, which restricts user freedom and may come with additional costs and limitations.