Distributed systems are a type of computing architecture in which multiple independent computers, often referred to as nodes or servers, work together to achieve a common goal. In a distributed system, the components are located on different networked computers that communicate and coordinate their actions by passing messages. These systems are designed to operate as a single, cohesive unit, despite being spread across multiple locations or even different geographical regions. Distributed systems are commonly used in scenarios where high availability, fault tolerance, and scalability are critical, such as in cloud computing, content delivery networks (CDNs), and large-scale web applications.

One of the key challenges of distributed systems is ensuring consistency and coordination among the different nodes, especially in the face of network failures, latency, and other issues that can disrupt communication. Techniques like consensus algorithms (e.g., Paxos, Raft), replication, and sharding are employed to maintain data integrity and system reliability. Distributed systems offer significant advantages, including improved performance, flexibility, and the ability to scale horizontally by adding more nodes as needed. However, they also introduce complexity in terms of system design, debugging, and security, making them a specialized area of study within computer science and engineering.