AutoCAD is a commonly used vector drawing application. Vectors include lines, arcs, and other geometry.
AutoCAD is a command-driven software application, meaning that it responds to commands (like LINE and ERASE) typed after the Command prompt at the bottom of the screen. AutoCAD has a ribbon, tabs, panels, and toolbars, but these are just alternative means of issuing typed commands. Since most of the commands have one- or two-letter shortcuts (L for LINE, E for ERASE, etc.), it’s usually much faster to type commands than to use the ribbon or toolbars.
AutoCAD has a long history in the architecture and design professions and continues to be used extensively for 2D (drafting) and 3D (modeling) work.
Its native .dwg file format can be read by most contemporary CAD applications (including Rhino, Revit, and SketchUp).
forums.augi.com/forumdisplay.php?176-AutoCAD for a forum discussion.