Free and open source software refers to software that is available without cost and allows users freedom to modify and share the software. Some key aspects are: - Free software focuses on liberty of users rather than price, allowing freedom to run, study, modify and share the software. - Open source refers to transparent software development that allows for distributed peer review to improve quality and reliability while reducing costs. - Free and open source software provides access to source code, ability to modify code, and no vendor lock-in, though hosting and support may have costs. - It is widely used for operating systems, servers, web applications, and embedded systems. Communities rather than single companies typically maintain free and open