Property Applies To Description
class HTML elements Adds the class attribute to the selected element.
CssClass ASP.NET Web server controls Adds the CssClass attribute to the control, which generates a class attribute for the resulting HTML element at run time.
style Most individual HTML and ASP.NET Web server controls If set from the VS.NET Properties window, uses the Style Builder to construct a style attribute for the element. Add the style attribute directly in the HTML editor.

Table 2 Use Object Properties to Apply Styles. Web pages you create with ASP.NET and VS.NET give you plenty of ways to apply styles to HTML. Some of the properties modify HTML attributes of both HTML and ASP.NET server controls, while others apply to one or the other.