Shape: A shape always has two dimensions, length as well as width. This is represented as an enclosed area that is defined by color, value, space, texture and form. When lines form together, they form shapes. Shapes can be geometrical, rectangles, ovals and squares. Form: A form always has three dimensions; length, width and height. Examples of such would be cubes, pyramids, spheres or even cylinders. Therefore, form has depth as well as height. Sculptures and decorative arts serve as good examples for form. Value: The value refers to the changes in the base color. This is also determined by how much light is reflected or absorbed by any surface. Values mean the various intensities of the tones or colors. This could be the highlights, midtones or even shadows in any painting or sculpture. Texture: The texture is the quality of a surface or the way any work of art is represented. There are three kinds of basic textures, actual, simulated and the invented texture. Lines and shading can be used to create different textures as well. For example, if one is portraying certain fabrics, one needs to give the feeling of the right texture so that it closely resembles what the artist is trying to convey. Color: Color always has three characteristics, which are hue, value and the intensity. Hue means the shades (Red, yellow or pink), value refers to the lightness or the darkness and intensity refers to the brightness or dullness of the work of art. Space: Space is the creation of visual perspective; this gives the illusion of depth. Space can also mean the way an artist uses the area within the picture plane. Real space is actually three-dimensional. The way any artist uses the combination of positive and negative space can have a great effect on his/her entire composition. The right use of space can go a long way in creating a bigger impact with even minimum use of lines. Three-dimensional space can be created with the help of shading and perspective to give a feeling of depth.
Also see The elements of art on The Getty