What's the difference between Spartan Sprint, Super, Beast, and Agoge?

Distance and, in general, extremeness.

Spartan Stadion  5K / 20 OBSTACLES

Spartan Sprint  5K /  20 OBSTACLES

Spartan Super 10K / 25 OBSTACLES

Spartan Beast Half Marathon / 30 OBSTACLES 

Spartan Ultra  50K / 60  OBSTACLES

Spartan Trail: 10K & Half-Marathon  / NO OBSTACLES

Hurricane Heat is 4 hrs hard group workout

HH12HR is 12 hrs hard group workout

HH24HR is 24 hrs hard group workout

The Agoge is minimum 60 hrs extreme race

Spartan KIDS Race is for 4 to 14,9 years old kids.