data cluster

In a computer system, a cluster is a group of servers and other resources that act like a single system and enable high availability and, in some cases, load balancing and parallel processing.

A cluster is a subset of objects which are “similar”. It is a subset of objects such that the distance between any two objects in the cluster is less than the distance between any object.

Clustering is a process of partitioning a set of data (or objects) into a set of meaningful sub-classes, called clusters. Clustering techniques are used for combining observed examples into clusters (groups) which satisfy two main criteria:

• each group or cluster is homogeneous; examples that belong to the same group are similar to each other.

• each group or cluster should be different from other clusters, that is, examples that belong to one cluster should be different from the examples of other clusters.

In personal computer storage technology, a cluster is the logical unit of file storage on a hard disk; it’s managed by the computer’s operating system. Any file stored on a hard disk takes up one or more clusters of storage. A file’s clusters can be scattered among different locations on the hard disk. The clusters associated with a file are kept track of in the hard disk’s file allocation table (FAT).

(disk structure: (A) track, (B) geometrical sector, (C) track sector, (D) cluster).