In the context of software development, "open source" means that the source code of a software program is freely available for anyone to view, modify, and distribute. This approach encourages collaboration and transparency, allowing developers to contribute improvements and new features. Open source software often fosters vibrant communities that share knowledge and support each other, leading to rapid innovation. Additionally, it can reduce costs for organizations, as they can utilize high-quality software without licensing fees. Open source projects provide opportunities for learning and skill development, making them valuable resources for both individual programmers and businesses.