Digital alias-free signal processing (DASP) is a technique for overcoming the problems of aliasing at extended frequency ranges. Based on non-uniform or randomised sampling techniques and the development of novel algorithms, it creates the capacity to suppress potential aliasing crucial for high frequency applications and to reduce the complexity of designs. (Wiley)

An example of aliasing can be seen in old movies, especially when watching wagon wheels on old Western films. Recall that occasionally the wheels appeared as if they going in reverse, even as the wagon would speed up. This phenomenon occurs as the rate of the wagon wheel's spokes spinning approaches the rate of the sampler (the camera operating at about 30 frames per second). (National Instruments)

The term aliasing refers to the distortion that occurs when a continuous time signal has frequencies larger than half of the sampling rate. The process of aliasing describes the phenomenon in which components of the signal at high frequencies are mistaken for components at lower frequencies. (Sampling and Aliasing)