The RadRibbonButton represents the basic button in the set of the RadRibbonView buttons. It inherits the RadButton control and extends its functionality in order to provide a better interaction with the RadRibbonView control.
To learn more about the RadButton control read its documentation.
Here is a sample definition of a RadRibbonButton:
<telerik:RadRibbonButton CollapseToMedium="Never" CollapseToSmall="WhenGroupIsMedium" IsAutoSize="True" LargeImage="Icons/32/Equation.png" Size="Large" SmallImage="Icons/16/Equation.png" Text="Equation" />