All paths are described internally in Inkscape (and in many
other drawing programs) as a series of Bezier curves. It is very
useful to understand the basic properties of Bezier curves for
drawing and manipulating paths. Bezier curves are defined by four
points, two of which are the *end* points or
*nodes* of the curve. The other two are
*control* points or handles, each paired with
one of the end points. The control points have the useful property
that a line starting at one end of the curve and ending at the
corresponding control point is tangent to the curve at the
end point. This enables the smooth joining of multiple Bezier
curves to form a path.

Two or more Bezier curves can be joined to form a more complex path. The node where they are joined may be smooth, indicated by a square.

Or
the node may be a *corner* node, also
referred to as a *cusp* node,
indicated by a diamond, where an abrupt change in
direction is allowed.

The segment between two nodes may be a *curve*
or a *line*. Note that there are no control
points for line segments.

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