What is a gv file and how do I open a gv file?

The GV file extension is used for a Graphviz Dot File developed by AT&T.  GV file is a document which includes descriptions about graphs and written using the DOT Language.  DOT Language is a simple text graph language that is used to interpret abstract representation of objects that is usually joined by links.  These objects are represented by vertices and edges which are called linked pairs.  Objects expressed in graphs are also being used in Discreet Mathematics. Different programs have the capability to process DOT files.  Among them are fdp, circo, twopi, neato and sfdp.  These programs interpret DOT files in GRAPHICAL FORM while programs like dotty, grappa, lefty, GVedit and KGraphEditor give an INTERACTIVE INTERFACE.  There are two types of graphs that can be used for DOT language.  The first is Undirected graphs which is considered as the simplest and used to describe relations between simple objects.  The last one is called Directed graphs which include dependency trees and flowcharts.