The area surrounding someone or something, together with the objects and circumstances in the vicinity; the environment or ambiance.
All parts of the universe that are not within the thermodynamic system of interest.
The topographical study of geographic locations or given places in relation to their history.
The properties of a particular technological embodiment that are not affected by differences in the physical layout or form of its application.
The arrangement of nodes in a communications network.
The branch of mathematics dealing with those properties of a geometrical object (of arbitrary dimensionality) that are unchanged by continuous deformations (such as stretching, bending, etc., without tearing or gluing).
Any collection τ of subsets of a given set X that contains both the empty set and X, and which is closed under finitary intersections and arbitrary unions.
The anatomical structure of part of the body.