Area is the quantity that expresses the extent of a two-dimensional figure or shape, or planar lamina, in the plane. Surface area is its analog on the two-dimensional surface of a three-dimensional object. Area can be understood as the amount of material with a given thickness that would be necessary to fashion a model of the shape, or the amount of paint necessary to cover the surface with a single coat. It is the two-dimensional analog of the length of a curve (a one-dimensional concept) or the volume of a solid (a three-dimensional concept).
Security is freedom from, or resilience against, potential harm (or other unwanted coercive change) from external forces. Beneficiaries (technically referents) of security may be persons and social groups, objects and institutions, ecosystems, and any other entity or phenomenon vulnerable to unwanted change by its environment.
A man wants no protection when his conduct is strictly right.
William Murray, 1st Earl of Mansfield, Bird v. Gunston (1785), 3 Doug. 275; reported in James William Norton-Kyshe, Dictionary of Legal Quotations (1904), p. 212.
To protect those who are not able to protect themselves is a duty which every one owes to society.
Lord Macnaghten, Jenoure v. Delmege (1890), 60 L. J. Rep. (N. S.) Q. B. 13; reported in James William Norton-Kyshe, Dictionary of Legal Quotations (1904), p. 212.