1. System Core Fragments
When a User dies, their System Core, the semi-digital interface bonded to their body doesn't vanish cleanly.
It fractures into small, crystalline data-objects known as System Shards (or just "shards" in slang).
Each shard contains a trace of:
i) the dead User's System data (skills, experience, fragments of code)
ii) a small amount of compressed energy (the System's "currency")
iii) and in rare cases, memory echoes; ghostlike imprints of the former User.
2. Why Scavengers Collect Them?
In the broken world after the Descent:
Shards are the new gold, they can be sold, traded, or used to recharge a living User's System.
Nulls (people without Systems) can't safely use them, but they can sell them to tech guilds or black markets.
Some users risk "direct shard absorption," which might grant random temporary boosts, but can also corrupt them into monsters.
So when scavengers loot a battlefield, they're not looking for valuables, they're harvesting System remnants from corpses.
That's what the gang in Chapter 4 is doing:
"Bag the shards first. That armor's still fused, cut the chip from her spine."
They're extracting core chips (solid shards) from dead Users' bodies to sell.