what is the 它 in 网络浏览器只允许一个小应用程序在给它提供服务的主机读取和写入数据, is 网络浏览器 or 小应用程序?
what is 套接字?
once the applet downloaded, it has nothing to do with the Server (Webserver, or the Host, where the Webserver is).
Applet can use io of the client machine (where the 网络浏览器 is), only if the client allows it, see class SecurityManager and google Applet Security Manager