From Halopedia, the Halo wiki
During the Battle for Zeta Halo, dozens of Spartan cores were scattered across the fragmented section of Zeta Halo. As John-117 ventured across the Ring, he collected any cores he came across and used them to upgrade his armor's abilities.
There are a total of 45 Spartan cores that can be collected in the Halo Infinite campaign. The player can use them to upgrade their various abilities: Grappleshot, shields, Threat Sensor, Drop wall, and Thrusters.
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