What is Partial Views in mvc ?

A partial view enables you to define a view that will be rendered inside a parent view. Partial views are implemented as ASP.NET user controls (.ascx).

When a partial view is instantiated, it gets its own copy of the ViewDataDictionary object that is available to the parent view. The partial view therefore has access to the data of the parent view. However, if the partial view updates the data, those updates affect only the partial view's ViewData object. The parent view's data is not changed.