(The majority of these definitions are from Artlex: http://www.artlex.com/)

Art Terms:

• Expression
  An attitude conveyed by the set of a person's facial features. Also, a quality of inner experience, the emotions of the artist (expressive qualities) communicated through emphasis and distortion
• Background
  The part of a picture or scene that appears to be farthest away from the viewer, usually nearest the horizon.
• Foreground
  The area of a picture or field of vision, often at the bottom, that appears to be closest to the viewer.
• Middle ground
  The part of an artwork that lies between the foreground (nearest to the viewer) and the background.
• Culture
  The entirety of socially transmitted behavior patterns, arts, beliefs, and all other products of human work and thought: decorative artifacts, environmental pollutants, high art, political ideologies, ritual beliefs, social customs, and so on.
  In anthropology, culture refers to the way of life of a human society, transmitted from one generation to the next by learning and by experience. Cultural universals include social organization, religion, structure, economic organization, and material culture (sometimes called visual culture). The spread of culture traits (customs, ideas, attitudes) among groups by direct or indirect contact is called diffusion. The general stages in cultural evolution are nomadic food gathering, then settled food producing, and finally urban dwelling.
  In the arts, the term is often used to refer to the expression of a particular period, class, or community, especially intellectual and artistic activity, and the works produced by it. Also, development of the intellect through training or education. And, culture can refer to a high degree of taste and refinement formed by aesthetic and intellectual training.
  

Types of Art Form:

• Portrait:
  A work of art that represents a specific person, a group of people, or an animal. Portraits usually show what a person looks like as well as revealing something about the subject's personality. Portraits can be made of any sculptural material or in any two-dimensional medium.
• Portraiture
  The field of portrait making and portraits in general.
• Self-Portrait
  A portrait an artist makes using himself or herself as its subject, typically drawn or painted from a reflection in a mirror.
• Landscape
  A painting, photograph or other work of art which depicts scenery such as mountains, valleys, trees, rivers and forests.
• Still life
  A picture of inanimate objects. Common still life subjects include vessels, food, flowers, books, and clothing.
  

Ways a subject is seated:

• Profile
  The side view of an object or person.
• Full-length
  The entire body of the subject is portrayed.
• Full-face or frontal: The head-on view of a person or object.
• Standing
  The subject is standing, as opposed to sitting or lying.
• Seated
  The person is sitting on a chair or a similar object.
  

Elements of art:

• Light
  Either the sensation of light, a source of light, its illumination, the representation of it in a work of art, or an awareness as if there were light on a subject.
• Texture
  An element of art which refers to the surface quality or "feel" of an object, its smoothness, roughness, softness, etc. Textures may be actual or simulated. Actual textures can be felt with the fingers, while simulated textures are suggested by the way the artist has painted certain areas of a picture.
• Shape
  An element of art, it is an enclosed space defined and determined by other art elements such as line, color, value, and texture. In painting and drawing, shapes may take on the appearance of solid three-dimensional object even though they are limited to two dimensions-- length and width. This two-dimensional character of shape distinguishes it from form, which has depth as well as length and width.
• Line
  A mark with length and direction (-s). An element of art that refers to the continuous mark made on some surface by a moving point. Types of line include: vertical, horizontal, diagonal, straight or ruled, curved, bent, angular, thin, thick or wide, interrupted (dotted, dashed, broken, etc.), blurred or fuzzy, controlled, freehand, parallel, hatching, meandering, and spiraling. Often it defines a space, and may create an outline or contour, define a silhouette; create patterns, or movement, and the illusion of mass or volume. It may be two-dimensional (as with pencil on paper) three-dimensional (as with wire) or implied (the edge of a shape or form).
• Space
  An element of art that refers to the distance or area between, around, above, below, or within things. It can be described as two-dimensional or three-dimensional; as flat, shallow, or deep; as open or closed; as positive or negative; and as actual, ambiguous, or illusory.
• Color
  Produced when light strikes an object and then reflects back to the eyes.
• Value
  An element of art that refers to the lightness or darkness of a color. Value is an especially important element in works of art when color is absent.