Rectangle[{xmin, ymin}, {xmax, ymax}] is equivalent to a suitable Polygon with four corners.
Graphics directives such as GrayLevel, RGBColor and Opacity can be used to specify how rectangles should be drawn.
FaceForm and EdgeForm can be used to specify separately how the interiors and boundaries of rectangles should be drawn. The default is that no explicit edge is drawn. »
The option RoundingRadius->r can be used to specify rounded corners rendered using circles of radius r.
Coordinates and lists of coordinates in rectangles can be Dynamic objects.
EXAMPLES
Basic Examples 
Scope 