Aliasing can occur in signals sampled in time, for instance in digital audio or the stroboscopic effect, and is referred to as temporal aliasing. Aliasing in spatially sampled signals (e.g., moiré patterns in digital images) is referred to as spatial aliasing.
This article explains the basics of aliasing and introduces the anti-aliasing technique used to combat it. Aliasing is a phenomenon that occurs during analog-to-digital (A/D) conversion due to insufficient sampling rates.
In fact, aliasing is the phenomenon in which a high frequency component in the frequency-spectrum of the signal takes identity of a lower-frequency component in the spectrum of the sampled signal.