A kind of optical disc used to store audio or other data.

A form of digital media on a plastic disc read by a laser in a CD drive. It comes in several varieties including CD-ROM, CD-R, and CD-RW.

(mathematics) Any topological subset of Euclidean space that is a compact set

plural of compact space

(sound engineering) The standard cassette tape format introduced in 1963 by Philips; an audio cassette.

Higher-density development in which a variety of land uses are located such that residents and workers are within walking distance of many destinations.

Higher-density development in which a variety of land uses are located such that residents and workers are within walking distance of many destinations.

(mathematical analysis) The property of a topological space that every sequence has a convergent subsequence.

(topology) Of a topological space: such that, for every point of the space, there is a neighborhood of that point whose closure is compact.

(mathematical analysis, of a set in a topological space) That is expressible as a countable union of compact sets.