A is for Articulation frame in a Federation starship's engine system. Uses dilithium crystals.
B is for BREACH!
C is for Cochrane, Zephram who developed human Warp flight.
D is for Dilithium Crystals of course. Much better than lithium crystals.
E is for Engineering, where the Warp Core is located.
F is for Factor, as in 'warp factor 3!'
G is for Great amounts of energy harnessed from the annihilation of matter and antimatter within a starship's warp reactor
H is for hydrogen ramscoops (those red glowy bits on the nacelles)
I is for Intermix chamber, an important part of the warp core