English riding saddles typically have billet straps on both sides of the saddle. Located under the top leg flap, these billets are used to attach the cinch to the saddle.
The billet strap setup on a dressage saddle is similar to that on an English saddle. Some dressage saddles will also have a fourth billet strap, called a point billet, to help further stabilize the saddle on the horse.
On a western saddle, the typical setup is for the saddle to have only a single billet on the off (right) side. Due to its location, this is called the off-billet.
They can have several billet straps like an English or Dressage saddle or they are going to use a single off-billet similar to a western saddle.