Open source projects are software initiatives where the source code is made publicly available for anyone to view, use, modify, and distribute. This collaborative approach encourages developers from around the world to contribute, leading to rapid innovation and improvement. Popular examples of open source projects include the Linux operating system and the Apache web server. These projects often rely on community support and contributions, allowing individuals to learn from each other and share their expertise. Open source projects can be found in various fields, including web development, data analysis, and even hardware design, fostering a culture of transparency and collaboration.