Armor or Gear in The Surge protects the player from damage as well as provides other gameplay benefits. It is not yet known what the specific armors are but this page will be updated as more information about the game is released.
Beyond defense, some armors increase the damage you deal, so if you have heavy exo on your arms it makes you more forceful. Besides that many armors have environmental effects. For example one armor turns on bright lights, a helmet that does the same thing. The game will also have environmental hazards like gas, and depending on the type of armor you have, you’ll get protection from it or mitigate its effects in some capacity. You can mix and match these effects depending on the scenario you’re getting into.
Core power is what powers the pieces of armor you equip. You can go up to a certain core power and no more and that’s part of your armor choice. Some armor uses more core power, some uses less. You could potentially use a low power set of armor but use implants as a balance. You can find the perfect balance of most defensive armor and implants or vice versa.