First, we will introduce some concepts and terminology that are important for understanding how the program works. This means that a graphic image is defined mathematically as objects composed of shapes, lines, curves, and points rather than as a collection of pixels. PostScript graphics offer several advantages. Images are composed of objects and their components instead of bit-mapped pixels. This means that these objects may be created and edited separately.
PostScript output is scalable in size and resolution too.
Instead of working with pixels to create graphic images, Illustrator defines an image as groups of objects defined by outlines. These objects have other characteristics besides shape and size, such as fill color, outline thickness and color, patterns and gradients, etc. A path is a line or curve between two endpoints. The endpoints define the limits of the path. In addition to endpoints, a path may contain other internal points.