javascript - このAngularJS式でパイプは何をしますか

Question

<div ng-controller="CartController">
     <div ng-repeat="item in items">
          <span>{{item.title}}</span>
          <input ng-model="item.quantity">
          <span>{{item.price | currency}}</span>
          <span>{{item.price * item.quantity | currency}}</span>
     </div>
     <div>Total: {{totalCart() | currency}}</div>
     <div>Discount: {{bill.discount | currency}}</div>
     <div>Subtotal: {{subtotal() | currency}}</div>
</div>

上記|のコードの - それは何をしますか?