Free and open-source software (FOSS) is a term used to refer to groups of software consisting of both free software and open-source software where anyone is freely licensed to use, copy, study, and change the software in any way, and the source code is openly shared so that people are encouraged to voluntarily improve the design of the software. This is in contrast to proprietary software, where the software is under restrictive copyright licensing and the source code is usually hidden from the users. FOSS maintains the software user's civil liberty rights (see the Four Essential Freedoms, below). Other benefits of using FOSS can include decreased software costs, increased security and stability (especially in regard to malware), protecting privacy, education, and giving users more control over their own hardware. Free and open-source operating systems such as Linux and descendants of BSD are widely utilized today, powering millions of servers, desktops, smartphones (e.g., Android), and other devices. Free-software licenses and open-source licenses are used by many software packages. The free software movement and the open-source software movement are online social movements behind widespread production and adoption of FOSS, with the former preferring to use the terms FLOSS or free/libre. Overview "Free and open-source software" (FOSS) is an umbrella term for software that is simultaneously considered both free software and open-source software. FOSS (free and open-source software) allows the user to inspect the source code and provides a high level of control of the software's functions compared to proprietary software. The term "free software" does not refer to the monetary cost of the software at all, but rather whether the license maintains the software user's civil liberties ("free" as in "free speech," not as in "free beer"). There are a number of related terms and abbreviations for free and open-source software (FOSS or F/OSS), or free/libre and open-source software (FLOSS or F/LOSS is preferred by FSF over FOSS, while free or free/libre is their preferred term). Although there is almost a complete overlap between free-software licenses and open-source-software licenses, there is a strong philosophical disagreement between the advocates of these two positions. The terminology of FOSS or "Free and Open-source software" was created to be a neutral on these philosophical disagreements between the FSF and OSI and have a single unified term that could refer to both concepts. Free software Richard Stallman's Free Software Definition, adopted by the Free Software Foundation (FSF),