Drawing:

 A picture or diagram made with a pencil, pen, or crayon rather than paint.

Sketch:

 A rough or unfinished drawing or painting, often made to assist in making a more finished picture

Illustration:

 a picture illustrating a book, newspaper, etc.

Outline: 

a line or set of lines enclosing or indicating the shape of an object in a sketch or diagram.

Cartoon: 

A simple drawing showing the features of its subjects in a humorously exaggerated way, especially a satirical one in a newspaper or magazine.

Artist’s impression: 

A sketch or drawing of someone or something, produced when no photograph is available.

Under-drawing:

 A sketch made by a painter as a preliminary guide and subsequently covered with layers of paint.