Hello there, if you don't have CTB and came to this page, please go here first. https://minecraft.curseforge.com/projects/call-to-battle-2-authentic-world-war-2-experience
The Call to Battle Auto-Updater does exactly what the name suggests, auto-updates Call to Battle and keeps it up to date.
It's highly recommended, although in most cases will be automatically downloaded with CtB. It is posted here so that it will be downloaded in the official Twitch Pack for CtB