Differences between Themes and CSS

• CSS usually deals with HTML code. You cannotapply CSS to certain ASP.NET specific server controls which are notpresent in HTML.

• You can apply Themes and skins to all ASP.NET controls with less effort. Themes and skins can be uniformly applied on both windows and asp.net applications.

• You can apply single theme to each page where as multiple style sheets can be applied to each page.

• Themes don't override or cascade style definitions by default the way CSS generally do. But you can selectively override local property settings for a control using StyleSheetTime attribute in Themes.

• You can include CSS files in Themes which is applied as part of Theme structure but not vice-versa.

You can apply theming for only those properties that have ThemeableAttribute attribute set to true in their control class.

Skins

Generally, Themes contain skins. A skin filecontains style definitions for the individual server controls. You candefine skin settings for a control using similar markup which we use toadd server controls to web page. Only difference you may find betweenskinned versions of control is that skinned version do not include IDattribute for control. You should retain properties for which you wantto configure through Themes. We create .skin files in Theme folder. Wecan also mix all server controls style definition in a single skinfile. Make sure all style definition files like CSS, skin files, Imagefiles and other resources are included in Themes folder in yourapplication directory.