Aliasing vs Imaging. What is imaging?
Aliasing is from decimation or undersampling with unwanted spectrum above the Nyquist rate of \$f_s/2\$
Imaging is from over-sampling duplicating the signal spectrum at harmonics of the sample rate according to the amount of sampling errors or false interpolation or in other cases intentional zeros added to the sample to up-convert the spectrum.
In the reverse process to aliasing, anti-imaging (or reconstruction) filters are used at the output of a sampled system to eliminate spectral images of the desired signal at harmonics of the sample rate.
The ideal filter specification is the same as that for the anti-aliasing filter. Any passband errors will have the same effect for both types of filter. The consequences for the rejection band deviating from the ideal are not the same, however, and depend on the response of the following equipment to the images that may be generated.
Both types of filter can be implemented in the analogue or digital domains.
Visual aid. with my markup in Blue/Yellow


There are many types of aliasing including; velocity aliasing , doppler aliasing, spacial aliasing, perceptual aliasing, diffraction gratings etc.

Undersampling is good when you can't sample above the carrier rate but have a lower rate stable enough to create an image that can be filtered easily.

Nonuniform sampling can facilitate digital alias-free signal processing (DASP)