This limitation is known as the same origin server security policy.

这项限制就是相同初始服务器安全性策略。

youdao

The origin server specifies the component's ETag using the ETag response header.

原服务器指定组件的ETag使用，ETag响应标头。

youdao

If no matching response can be found, the request is forwarded to the requested origin server.

如果没找到匹配请求，则将请求转发到所请求的原始服务器。

youdao

Gamers struggled to download the game from the Origin servers and, once they had it, they struggled to find a server with enough room for them.

FORBES: Maxis Working to Fix SimCity's Server Problems