[S.T.F.U.]

From FSM for a 87 Samurai! Explain please!

 

[Flashover Mfg]

No. Side gears are splined internally to hold the axle shafts. Spider gears are the same size, and engage the side gears but are held by the cross pin (pinion shaft as named on your drawing).

 

[Pazuzu]

Side gears are aligned like the ring gear, and just spin around.
Spider gears are sideways from them, and whip around in circles.

You'll recognize them when you get in there.

 

[Tim84K10]

That axle has two side gears, and four spider gears, also referred to as pinion gears in the above drawing (not to be confused with the pinion gear that meshes with the ring gear).