Using the clip object we can retain signal within a selected range. Anything above max is clipped at max, and anything below min is clipped at min.
Here min = -0.5 and max = 0.5. The audio signal from an osc~ goes from -1 to +1. This signal will be clipped between half of that range.
The sinusoidal wave was only one frequency. But because of the distortion now we will have many frequencies present.
Now the waveform is more square-wave like:
The frequency spectrum (in Audacity, Effects menu and Plot Spectrum option) shows the importance of higher frequencies: