Reply To: Purpose of the star junctions

what you call a star junction is also known as an extrusion pole, it is half of a partnership with the nose pole…

this illustration is in 3D mode but it is an inset if you lay it flat, like around the eyes it allows you to inset a loop (or extrusion)…

it takes 4 of them to make the loop complete.

if you can command these two types of poles you will rule retopology…

hope this is helpful