Colinear  -  Lying in one line (usually refers to a set of points).

Congruent  -  Of exactly the same size and shape; in other words, of exactly the same dimensions.

Coplanar  -  Existing in one plane (usually refers to points or lines).

Dimension  -  The number of lines required to span a region in space.

Line  -  A collection of points arrayed in a straight formation without limit.

Noncolinear  -  Not lying in one line (usually refers to a set of points).

Noncoplanar  -  Not existing in one plane (usually refers to points or lines).

Perpendicular  -  At a 90 degree angle (something is perpendicular relative to something else).

Plane  -  A flat, boundless surface in space.

Point  -  A specific location in space.

Ray  -  A portion of a line with a fixed endpoint on one end that extends without bound in the other direction.

Segment  -  A portion of a line with two endpoints and, thus, finite length.

Space  -  The collection of all points.