Durga is Sundari Rajarajeshwari
...................................the empress of the cosmos..................................................

Unlike the goddess kaali (काली )who represents the dark gruesome aspect of durga(adiparashakti),devi sundari(सुंदरी )represents her benevolent facet!!!!!!!!

Shakti or the primal force is without any attribute ,she is formless,nameless,uncomprehendible.....so she is called durgeya(the unknowable) and durga (the inaccessible)!!!!!!!!

.......................for easy access,shakti hasbeen conceived either as the all absorbing entity(काली )or the ever producing and balancing entity (श्री )..........................

according to science......only when matter and energy are in harmony does the universe exist,matter when devoid of energy ceases to function......matter is like shiva ,after creation....devi durga parmeshwari unites with shiva as shri tripurasundari.........sitting above shiva lyk a throne......thus bringing matter and enrgy together for the functioning of the cosmos..........................

................................again when entropy begins to increase with total energy remaining constant(entropy can be considered the wrath of devi at the state of the world)....durga parameshwari abandons her husband,who then becomes lifeless....shakti becomes wild ,untamed and malevolent..and proceeds towards the dissolution of the cosmos...it is then she is called kaali...the dark night of dissolution!!!!!!!!!!!!!!!!!

.........................................om shakti parashakti.................................................................................