Difference between coregistration and collocation

What is the difference between coregistrate (Radar->Coregistration->Coregistration) and collocation (Raster->Geometric Operations->Collocation)?

Of course there is some differences in SNAP menu. For example coregistration uses warp function in order to apply distortions to slave image. I don’t see any other option in collocation besides “resampling”.

I have read the tool help but still not clear…

Collocation help:

The Collocation Tool allows to collocate two spatially overlapping products. Collocating two products implies that the pixel values of one product (the slave) are resampled into the geographical raster of the other (the master).

Coregistration help:

Coregistering InSAR Products
The sub-pixel coregistration of SAR images is a strict requirement and critical component of any interferometric processing chain. It is an essential step for the accurate determination of phase difference, and applications such as DEM map generation, interferometric deformation analysis, etc.