Line (noun) - A line is a basic element of art, referring to a continuous mark, made on a surface, by a moving point. A line is long relative to its width. It can define a space, create an outline or pattern, imply movement or texture and allude to mass or volume.
Shape (noun) - A shape is an enclosed space, the boundaries of which are defined by other elements of art (i.e.: lines, colors, values, textures, etc.). Shapes are limited to two dimensions: length and width.
Form (noun) - form is a three-dimensional geometrical figure (i.e.: sphere, cube, cylinder, cone, etc.), as opposed to a shape, which is two-dimensional, or flat.
Color (noun) - Color is the element of art that is produced when light, striking an object, is reflected back to the eye.
Value (noun) - value refers to the lightness or darkness of a color.
Space (noun) - space refers to distances or areas around, between or within components of a piece.