MapReduce is a programming model and an associated implementation for processing and
generating large datasets that is amenable to a broad variety of real-world tasks. Users
specify the computation in terms of a map and a reduce function, and the underlying runtime
system automatically parallelizes the computation across large-scale clusters of machines,
handles machine failures, and schedules inter-machine communication to make efficient
use of the network and disks. Programmers find the system easy to use: more than ten …

MapReduce is a programming model and an associated implementation for processing and
generating large data sets. Users specify a _map_ function that processes a key/value pair
to generate a set of intermediate key/value pairs, and a _reduce_ function that merges all
intermediate values associated with the same intermediate key. Many real world tasks are
expressible in this model, as shown in the paper.