What are vector objects?
Vector objects are graphic elements defined by a path made up of points connected by line segments (curved or straight). When you increase the magnification of a vector object, it retains its sharp outline, unlike a bitmap object, which starts to break up into pixels as the magnification increases. Vector objects may be scaled up and down without losing detail. They are geometric definitions rather than drawings. The line segments of a vector object can have properties attached to them (color, stroke width, texture etc), and, if the path of the object is "closed" (that is, if the start of the path connects to the end, to close the loop), you can also fill the enclosed area with textures, color, gradients etc. Anything you can do with a bitmap element you can do with a vector, but quicker and more flexibly, and a great deal more besides.
A vital part of manipulating vector objects is the Bézier curve. This is a mathematically generated curve that determines the shape of the line segment between two points on the vector path. Like the French curves used by a draftsman, you can create complex smooth shapes very easily with Bézier curves. The key to manipulating Bézier curves are the "Bézier handles", control handles that are attached to each point that defines the vector path.
If you use the Pen tool to draw to points to create a simple line segment, the segment defaults to a straight line. If you activate the Bézier handles on one of the points on the line (see below), you can warp it into a host of different curved arcs. But this is where confusion starts: creating a handle to control the curve seems at first to be an arbitrary and capricious process. Bézier handles are weird until you get to know them – after that they become your best friends.
To help you understand how they work, we'll start by describing the various types of handles. Then we'll show you simple ways to add, remove and change between the different sorts. After that, it's playtime, and we'll let you loose to experiment on a few vector objects. Once you've mastered these simple examples, Bézier curves will be one of the most useful things you'll know about Fireworks.