The red lines depict the paths (loci) of the 4 dots if we were to adjust the frequency and amplitude of the sinusoid along the solid red segment (between fs/2 and fs). No matter what function we choose to change the amplitude vs frequency, the graph will exhibit symmetry between 0 and fs. This symmetry is commonly referred to as folding, and another name for fs/2 (the Nyquist frequency) is folding frequency.[5]