Conduits are a system which allows an additional level of customization to your Souldbind with bonuses that are specific to your class and or spec. They are categorized into three types: Potency (Throughput), Endurance (Survival), and Finesse (Utility). Conduits have ranks which allow you to upgrade the power of your Conduits.
A Conduit can only be be used once per Souldbind at a time, ie. if you are using a particular Conduit in a Soulbind socket, you can't reuse that Conduit in a different socket for that same Soulbind. You can, however, use that Conduit in a different Soulbind.
Conduits can only be reset and reselected at the Forge of Bonds in your Covenant Sanctum once a week. This is mitigated by the ability to change Soulbinds and respec them at will, so you can use a Soulbind's left hand path for one spec and right hand path for another, or have one Soulbind for each spec if you so desire.
Once you have collected a Conduit, it remains in your collection and is not destroyed when replaced in your Soulbind.
Where to Get Conduits
Conduits can be acquired as rewards from playing max level content: Dungeons, PvP, Raids, Reputations, World Quests, etc. Most Conduits will be available from more than one source, allowing flexibility of acquisition across content types. Conduits are a persistent collections system, similar to Essences in Battle for Azeroth. When you acquire a Conduit, you add it to your Conduit collection in your Sanctum. When you acquire a higher ranking version of a Conduit that you have already collected, adding it to your collection upgrades your current version, making it more powerful.