Extents
Extents is a term used in several disciplines to denote reach, range, or allocated space. In general topology, the extent of a topological space X is the supremum of the cardinalities of its closed discrete subspaces. This invariant measures how large closed discrete subsets can be, and it is studied alongside density, weight, and other size characteristics of spaces. In specific contexts, such as compact or separable spaces, the extent interacts with these invariants in ways that illuminate the structure of X.
In geometry and real analysis, the extent of a bounded subset of the real line is the
In geography and geographic information systems, geographic extent (or bounding extent) describes the minimal axis-aligned rectangle
In computing and storage, an extent is a contiguous region of storage allocated to a file or
Other common uses include referring to the extent of a territory or the general scope of a