Distributed systems refer to a network of interconnected and autonomous computing devices that work together to achieve a common goal. These systems are designed to be scalable, fault-tolerant, and highly available, allowing them to handle large amounts of data and user requests in a decentralized manner. Distributed systems are commonly used in cloud computing, peer-to-peer networks, and content delivery networks, among other applications. Researchers in this area focus on developing algorithms, protocols, and architectures that enable efficient communication, coordination, and resource sharing among the nodes in a distributed system. They also study the challenges and trade-offs related to consistency, reliability, security, and performance in distributed systems.