The waveform that a multivibrator can produce is a rectangular wave.

Multi-harmonic oscillator is an oscillator that uses deep positive feedback to make two electronic devices switch alternately through resistance-capacitance coupling, thus generating square wave output by self-excitation. Usually used as a square wave generator.

Multi-oscillator is a kind of self-excited oscillator which can generate rectangular wave, also known as rectangular wave generator. "Multi-harmonic" means that rectangular waves contain rich higher harmonic components in addition to fundamental components. The multivibrator has no steady state, only two transients. When working, the state of the circuit automatically alternates between these two transients, thus generating rectangular wave pulse signals, which are often used as pulse signal sources and clock signals in sequential circuits.