Difference between CSS and Themes in asp.net

CSS	Themes
Applies to all HTML Controls	Applies to all the server controls
Is applied on the Client Side in the Browser	Is applied on the server rather than in the browser
Cannot be Applied through the configuration files	Can be Applied through Configuration Files.
Can be used directly via a reference to the css file location	All theme and Skin files should be placed in a special Asp.net folder called the “App_Themes” in order for the themes to work and behave normally.
Do not require any other resource like Skin files	Each theme should be associated with at least one Skin file.
CSS prioritizes a property to the nearest element present.	Themes overwrite the properties of the individual control by its own