Bhavik,

like your query will try to keep my reponse clear n specific ;)

"Now where i am struggling is the Web Framework,I can't understand how frame work is dealing with javascript and XMl or HTML,CSS. For examlple ,when i write :"

-> with regards to Javascript it uses some jquery libraries major of them are underscore.js and backbone.js n mostly the  whole system works on backbone.js framework, w.r.t underscore.js in simple term "it is a kind of supporting actor to minimize your data manipulations burden" , so a walkthrough here could help you to undrestand the flow..

-> regarding views everything is rendered from xml templates which could be found web/static/src/xml/base.xml and base_common.xml, etc...(mostly in web module only)

Now there are seperate jquery(backbone) classes created for different kinds of views which could be found at web/static/src/js/views/tree_view.js(for tree view) or form_view.js(for form view), etc(graph_view.js, list_view.js,....)....

and more of it on "how odoo works", its functionality like save/editing of data, sessions manipulations, models(classes) , registry, and other common utilities can be found at web/static/src/js/framework/

in brief i can say the answer for most your query regarding "Web Framework" could be found here in "web" module... explore it and you can hit the odoo client end very easily...
Hope it will give u some reference to your query..