How does the Saraswati veena differ from the Rudra veena?

The Saraswati veena is a Carnatic lute, with a jackwood body and 24 frets fixed in wax, and it descends from earlier lute forms. The Rudra veena of Hindustani music is a zither. Players of both push strings sideways on the frets to raise the pitch, up to a fifth on the Rudra veena, so that technique does not separate the two.