Difference Between Coil and Coil Pack

This is probably child's play, but I don't work on my truck enough to know this one. Engine light came on and the code read "Cylinder 4 Misfire". So, I need to change my ignition coil (apparently).

Here's my issue: the actual coil for Cylinder 4 is inserted in Cylinder 1 (which connects to a coil pack (I think) in Cylinder 4 via wire). As far as I can tell, Cylinder 4 contains a coil pack, not the coil itself.

Here's my question: do I need to only replace the coil pack in Cylinder 4? Do I need to replace the coil, and coil pack?

(I understand it might be necessary to replace spark plugs, wires, etc. I'm really just looking for an answer regarding the coil vs. coil pack).

 

Coil is single, one per cylinder.
Coil pack has at least two coils in one unit.
Most modern vehicles have coil packs.
Which engine?

 

Thanks, Lance. It's a 2003 TRD 6-cylinder (3.4 liter). I believe this is the corresponding chart:



The coil itself is located at Cylinder 1, which connects to a boot (?) (I assumed it was what's referred to as a coil pack, but I guess I'm off) at Cylinder 4.

 

These are old shool “waste spark” systems. The cylinder on bank 1 has the coil pack, which also has a lead for a wire that then runs to the opposing cylinder that’ll be at TDC but on the end of the exhaust stroke. This system fires both of those cylinders are the same time, saves on cost at the cost of more limited control, hence why these trucks are single bank instead of a more typical 2 bank setup on a v6

 

This photo shows that 1 and 4 are connected in the sense of position but with cam timing they’re on different strokes