The term "open-source" refers to software development models where the source code is freely available for anyone to view, modify, and distribute. This collaborative approach promotes community involvement, innovation, and transparency, as developers from around the world can contribute to the project. Open-source projects often lead to rapid improvements, as users identify and fix bugs, add features, and create applications based on the original code. Well-known examples of open-source software include Linux, Apache, and Mozilla Firefox, which underscore the success of this model.