What is different same function in assets.php vs. Assets.php?

What is different in using and prozess from removeAssets methode?

i have this : modules/Cockpit/Controller/Assets.php
and this : modules/Cockpit/module/assets.php

in same scripts can i finde methode removeAssets

i am not understand whats is the different in use.
it is legacycode in one of them?