This document summarizes distributed computing. It discusses the history and origins of distributed computing in the 1960s with concurrent processes communicating through message passing. It describes how distributed computing works by splitting a program into parts that run simultaneously on multiple networked computers. Examples of distributed systems include telecommunication networks, network applications, real-time process control systems, and parallel scientific computing. The advantages of distributed computing include economics, speed, reliability, and scalability while the disadvantages include complexity and network problems.