Adobe CS5 Illustrator Pen Tool Fundamentals
The Adobe Creative Suite 5 (Adobe CS5) Illustrator Pen tool can be used to create elements, such as straight lines, curves, and closed shapes, which you can then incorporate into illustrations.
Bézier curve: Originally developed by Pierre Bézier in the 1970s for CAD/CAM operations, the Bézier curve became the underpinnings of the entire Adobe PostScript drawing model. A Bézier curve is one that you can control the depth and size of by using direction lines.Bézier curves are controlled by direction lines.
Anchor point: You can use anchor points to control the shape of a path or object. Anchor points are created automatically when using shape tools. You can manually create anchor points by clicking from point to point with the Pen tool.
Direction line: These lines are essentially the handles you use on curved points to adjust the depth and angle of curved paths.
Closed shape: When a path is created, it becomes a closed shape when the start point joins the endpoint.
Simple path: A path consists of one or more straight or curved segments. Anchor points mark the endpoints of the path segments.