Rubber banding is a very simple, but useful technique for positioning. The user, if he wants to draw a line, say, specifies the end points and as he moves from one point to another, the program displays the line being drawn. The effect is similar to an elastic line being stretched from one point to another and hence the name for the technique. By altering the end points, the position of the line can be modified.
The technique can be extended to draw rectangles, arcs, circles etc. The technique is very useful when figures that pass through several intermediate points are to be drawn. In such cases, just by looking at the end points, it may not be possible to judge the course of the line. Hence, the positioning can be done dynamically, however, rubber band techniques normally demand fairly powerful local processing to ensure that lines are drawn fast enough.