Progression in Borderlands 4 is deeper than it's ever been, largely because you actually unlock new items and systems as you go, from more weapon parts to class mods, enhancements, and firmware. Effectively serving as gear set bonuses found in MMOs, firmware is crucial to your endgame build, though finding what you need is like searching for a needle in a haystack.
You'll start getting occasional gear drops with firmware bonuses at around level 25—these items will have a unique glow, no matter the rarity. If you're lucky, you'll get the perfect firmware for your build, and it'll serve you well for quite some time. However, since it's attached to your gear, you'll inevitably swap it out for something higher level soon enough, tossing it in the trash like almost everything else while you're levelling. But you shouldn't.
