Items are objects and artifacts that provide special benefits and/or bonuses to Shells beyond their basic capabilities. Depending on their type, they're equipped either manually or automatically as soon as you come into contact with them. While most items can be adquired by any shell, they cannot be used by all of them.
Items of the same kind have the same base stats, but may have different modifiers. Modifiers add additional stats to the item, up and above its base stats (Except for damage, which is calculated into its base stat). They go in order, as shown from least to greatest. However, you may prefer a lower rank over a higher rank, as the lower rank gives stats in better categories than the higher rank.