Bringing the plasma up to fusion temperatures is done with the injection of neutral atoms and the excitation of different types of plasma waves. In addition, waves are also used to drive the plasma current without using transformers — so-called nonin­ductive current drive. There are many physics problems involved in these processes. Neutral beams also fuel the plasma and give it rotational velocity. Waves not only heat the plasma and drive its current but are also used to change local conditions inside the plasma and shape the current profile. In this chapter, we are concerned with technology and therefore concentrate on the hardware and discuss only the main types of waves that can be used.