上一篇介绍的四种Internet基本服务功能为用户检索和获取Internet信息资源提供了有效的工具和手段。然而,使用之后用户会发觉,有些服务功能使用起来不甚方便,如用户常常为不知道信息资源主机的地址而发愁,或者要记一些烦琐的命令集等。因此,在Internet信息资源以惊人速度增长的今天,寻求检索信息更简单、方便、有效的方法成为Internet开发研究者研究和努力的目标。目前,一些大学、软件公 The four basic Internet service features described in the previous section provide effective tools and tools for users to retrieve and retrieve Internet information resources. However, after use, users will find that some service functions are not easy to use. For example, users often have to worry about not knowing the address of the information resource host or remember some cumbersome command sets. Therefore, with the rapid growth of Internet information resources, searching for information in a more simple, convenient and effective way has become the goal of research and efforts of Internet developers. At present, some universities, software companies