A contour is the line which defines a form or edge - an outline. Contour drawing is the place where most beginners start, following the visible edges of a shape. The contour describes the outermost edges of a form, as well as dramatic changes of plane within the form. Put simply, a contour line drawing is an "outline drawing," that uses no shading.
A contour drawing is done when the artist looks intently at the EDGES of an object, but rarely looks at the paper while the pencil moves. The goal of contour drawing is to make a line that is authentic and true to what you are actually seeing, and to train your hand to copy your eye's movement.
There are several different types of contour line drawings:
'Blind contour drawing' is when contour drawing is done without looking at the paper AT ALL.
This helps train you to look more often at your subject than look at your paper. Staring down at your paper while drawing can be a hard habit to break~
"Continuous line contour drawing' is a contour drawing done without picking your pencil off of the paper. It is essentially done with one long line. Continuous line contour drawings can be done 100% "blind" or not.