Distributed computing

A computing model in which multiple networked computers coordinate to perform tasks, share resources, or provide services. Its defining challenge is coordinating work despite communication delays and component failures.

Message passing: A communication method in which processes exchange data by sending and receiving messages. Networked computers use messages to coordinate without sharing a single memory space.
Computer network: A set of connected devices that exchange data using communication protocols. Distributed computers depend on networks to exchange requests, results, and state.
Distributed database: A database whose data is stored across multiple networked computers. It applies distributed coordination to persistent data storage and queries.
Parallel computing: A computing approach that performs multiple operations simultaneously to solve a problem faster. Parallelism can occur within one tightly coupled machine; distribution requires networked coordination.
Remote procedure call: A protocol that lets a program invoke an operation on another computer as though it were local. It hides message exchange behind a procedure-call interface.
Concurrency: The execution of multiple tasks whose operations overlap in time. Independent machines perform work simultaneously, creating ordering and coordination problems.
Distributed file system: A file system that stores and serves files across multiple networked computers. It makes storage distributed while presenting a unified file interface.
Centralized computing: A computing model in which processing and control are concentrated in a central system. It avoids some coordination problems by keeping authority and work in one place.
Distributed consensus: The problem of getting networked processes to agree on a value despite failures or delays. Replicated services need agreement on decisions such as which update comes first.
Replication (computing): The maintenance of copies of data or services across multiple computers. Copies can improve availability and performance but require synchronization.

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