If you look at the pilot/ship cards, you'll see a string of symbols along the bottom. They work like equipment "slots". Look at Luke's X-Wing from the base game: you'll see one symbol that looks like a military medal, the "gem" (which FYI is a proton torpedo warhead), and one that looks like R2.
That means he can equip 1 Elite Pilot Talent, 1 Torpedo, and 1 Astromech.
If you look at Biggs, he can equip a Torpedo and an Astromech, but no Elite.
Black Squadron pilots can take an Elite (as befits the better personnel assigned to the Death Star), but a rookie Academy Pilot in a basic TIE fighter has nothing.
Each ship can also include one Modification, and one Title, which are never indicated on the ships themselves (since they are universal).
The cards are always interchangeable on any ship that has an available "slot" of that type, unless the card expressly says otherwise.
So, again included with the base game, you have cards for Determination and Marksmanship (Elite), Proton Torpedoes (Torp), R2-D2 and R2-F2 (Astromechs).
You can give Luke Marksmanship, Proton Torps, and R2-D2, and give Biggs Determination and R2-F2. You could equally put Determination on Chewbacca (in the Falcon), or put Draw Their Fire (Elite from the Falcon pack) or Ion Torpedoes (from the Decimator pack) on Luke.
This is where the army-/list-building aspect of the game lies: looking at the inherent capabilities of a ship, plus its pilot's ability, and choosing upgrades that complement them as well as fit into a list with other ships.
Got it?
- H8