The Librem runs PureOS as it’s operating system. This operating system is based upon the Linux kernel and is viewed by privacy and security experts as being incredibly secure. This is due to it being free software where the source code is available, meaning that people with proper technical skill can easily read, view and understand the language of the operating system. Operating systems that you are used to such as Windows and OS X are non-free and the source code is held by Microsoft and Apple. This non-free software, where the source code is not available in proprietary OSes makes it impossible to fully read and understand the computer language thereby making it impossible to fully know what your Microsoft or Apple based computer is doing or if it is secure.