Many modules have use in both. In general it is the overall fit that dictate what the ship is good for.
Guns, tank are needed for both. A good bunch of E-war can also be used in both PvE and PvP situations (for instance, webbing works against both players and NPC targets).
As for the tank, the simplefied difference between a PvE ship’s tank and a PvP ship’s tank are:
- With PvE you know what you will fight, so you can look up what damage types will inflict damage to you and you can fit a specified tank for that. If an NPC only deals EM/Thermal damage, you tank those things and don’t look at Kinetic/Explosive at all.
Where as with PvP, in general, you will not know what the other player(s) will bring to the field, so you will have to account for all 4 damage types.
- With PvE, in general you will have to tank a lower amount of volley damage/DPS but for a longer extended timeframe. So you need a sustainable tank but don’t really need huge amount of EHP.
While in PvP, most battles are short and furious. You either die, your enemy dies, or either of you gets away from the fight. So you want to soak up a lot of damage in a really short time.
- Same can be said with capacitors, PvE you want a capacitor situation that let’s you run your stuff for an extended amount of time (doesn’t have to be cap stable). Say, your worst mission will take you 10 minutes, then having a capacitor that drains in 13 minutes is good enough.
In PvP, most battles (big ass slugfest excluded) will not last more then a couple of minutes, if that at all. So “saving” capacitor for later is a bit of waste, use it while you are alive to kill the other quicker.
But as you said, you are in a corp. Ask around in corp what would be benefitial for you to look for so you can join in on more fun things.