Mods

Mods are a form of upgrade in Destiny 2. They are used to boost the potency of weapon perks, change weapon stats, provide bonuses for Exotic weapons via Catalysts, and add or improve features onto a piece of Armor. Some mods can also be equipped onto Ghost shells, and provide a variety of bonuses.

Weapon mods
Weapon mods are those that can be slotted into any Legendary weapon released during or after the Forsaken expansion. Almost all of them can be used an infinite amount of times upon acquisition, but there are a few that are single use. A full list of weapon mods can be found below (any info in italics was gathered from the Community Research section of each mod on Light.gg):