The Robot Operating System (ROS) is an open source set of software libraries and tools designed to aid in building robot applications. It provides services expected from an operating system, including hardware abstraction, low-level device control, implementation of commonly-used functionality, message-passing between processes, and package management. ROS offers tools and libraries for obtaining, building, writing, and running code across multiple computers. At its core, ROS provides a message-passing system, often called "middleware" or "plumbing," which manages communication between distributed nodes via an anonymous publish/subscribe pattern. This system is crucial for implementing new robot applications or any software system that interacts with hardware. ROS is a meta-operating system for robots, offering hardware abstraction, device drivers, libraries, visualizers, message-passing, package management, and more. It is licensed under an open source, BSD license.