<apex:facet> component is used to specify content in an area of a Visualforce page and it provides information about the data in the parent component. For example, we can use a facet component in the header or footer of a
<apex:dataTable>. We can override the default facet of a Visualforce component by using the
<apex:facet> component. The advantages and disadvantages of the facet component are as follows with an example:
<apex:facet>component cannot be used directly in Apex; it must be a child component of another Visualforce component. We can use that in a dynamic component.
<apex:facet>component that is used with ...