Is JSF validation client-side or server-side?

I implemented my validation logic as follows:

        <h:inputText id="title" value="#{...}" 
            required="true" requiredMessage="...some..text..." 
            validatorMessage="...some..other..text..." >
            <f:validateLength minimum="10" maximum="50"/>
        </h:inputText>

I read a lot about clientside and serverside validation and about their advantages and disadvantages. But I have no idea about what the code above does.

Can somebody please explain that :-)

Cheers