CADSTAR is part of a printed circuit board design suite that provides a solution
to the needs of anyone that needs a printed circuit board for their electronic products.
CADSTAR has a schematic diagram editor where you can draw first class (or really bad) circuit diagrams to show how your PCB works. A PCB editor that enables you to setup your PCB, use DXF provided outlines of mechanical details and place your components accurately and following many design rules to ensure that your design fits where it will go.
Then there is the Placement and Routing program that enables you to create the tracks for all your connections, also move components to improve the tracking, flood ground planes and copper pour with high speed options that allow differential pairs, BGA fan outs of pads, length, delay and impedance controlled routing and all sorts of other stuff that go into laying out the perfect PCB.
CADSTAR also has an excellent library editor and management suite with symbol and component wizards that enable quick and easy creation of even the most complex symbols and components.
There are further add on's such as the BoardModeler Lite that allows you to view your PCB in 3D, check it against physical constraints such as enclosures and make sure everything fits and does not clash, even move the components so that they are not hitting the enclosure and pass that information back to CADSTAR.
A few 3rd party tools have also been created in order to do those little things that CADSTAR does not do natively, but I may mention those another day.
The end of all this is that once you actually understand how CADSTAR actually works and how to use it to its best then making a good PCB that works right first time.