There are many different kind of waveforms like sine wave, cosine wave, square wave, triangular wave, sawtooth wave, pulses, spikes, stair-case wave, ramp etc. All these waveforms are generated using oscillator circuits.Waveform converter circuits convert one type of wave into other. The function generator itself uses such circuits to generate different kinds of waveforms. These circuits are very much useful when some circuits require one specific kind of wave as an input.