Analysis of information sources in references of the Wikipedia article "Frekuensi Nyquist" in Malay language version.
The Nyquist frequency is that frequency whose period is two sampling intervals.
the existence of power in the continuous signal spectrum at frequencies higher than the Nyquist frequency is the cause of aliasing error
Frequencies "fold" around half the sampling frequency - which is why [the Nyquist] frequency is often referred to as the folding frequency.