What is Target Server configuration in Apigee and why is it used instead of hardcoding backend URLs?

<!-- TargetEndpoint using a TargetServer (recommended) -->
<TargetEndpoint name="default">
  <HTTPTargetConnection>
    <LoadBalancer>
      <!-- Reference a named Target Server instead of hardcoded URL -->
      <Server name="orders-backend-server"/>
    </LoadBalancer>
    <Path>/api/v1</Path>
  </HTTPTargetConnection>
</TargetEndpoint>

<!-- Target Server definition (set in Apigee UI/API per environment) -->
<!-- Environment: prod -->
{
  "name": "orders-backend-server",
  "host": "orders.prod.internal.example.com",
  "port": 443,
  "sSLInfo": {
    "enabled": true,
    "clientAuthEnabled": false
  },
  "isEnabled": true
}

<!-- Environment: dev -->
{
  "name": "orders-backend-server",
  "host": "orders.dev.internal.example.com",
  "port": 8080,
  "sSLInfo": { "enabled": false }
}

<!-- Load balancing across multiple target servers -->
<LoadBalancer>
  <Algorithm>RoundRobin</Algorithm>
  <Server name="orders-backend-1"/>
  <Server name="orders-backend-2"/>
  <Server name="orders-backend-3"/>
</LoadBalancer>