Button

Buttons are used for ajax, non-ajax actions and navigations.
Source

<h:form>
    <p:commandButton value="Default" type="button"/>
    <p:commandButton value="Icon left" type="button" icon="ui-icon-check"/>
    <p:commandButton value="Icon left-float" type="button" icon="ui-icon-check" iconPos="left-float"/>
    <p:commandButton value="Icon right" type="button" icon="ui-icon-refresh" iconPos="right"/>                
    <p:commandButton value="Icon right-float" type="button" icon="ui-icon-refresh" iconPos="right-float"/> 
    <p:commandButton value="Inline" type="button" icon="ui-icon-delete" styleClass="ui-button-inline" />
    <p:commandButton type="button" icon="ui-icon-info" />
    <p:commandButton value="Ajax" />
    <p:commandButton value="Non-Ajax" ajax="false"/>
    <p:commandButton value="Theme" type="button" icon="ui-icon-delete" styleClass="ui-button-b" />
    <p:commandButton value="Mini" type="button" styleClass="ui-mini"/>
    <p:button value="Go Button" outcome="index" icon="ui-icon-info"/>
    <p:button value="Font Awesome icon" outcome="index" icon="fa fa-history"/>
</h:form>