Open-Source Software (OSS) is computer software that is released under a license allowing anyone to modify, distribute, and use the software for any purpose. This means that its source code is publicly available and can be accessed, modified, and shared by individuals or communities of developers. Knowledge of OSS may involve an understanding of programming languages, version control systems, and collaborative development tools. Many businesses and organizations rely on OSS for their operations, and contributing to open-source projects can be a valuable skill in the tech industry.