In the last part , the author analyzes the types and principles of www , a hyper - text information retrieving tool , and sums up the characteristics of some search engines most in use by means of tables . taking google as an example , the author also looks forward to the future of the developing trend of search engines 最后,論文對超文本信息檢索工具? ? www的類型、工作原理進行分析,以列表方式對一些常用搜索引擎的特征進行總結,并選取www上新一代搜索引擎google為典型代表,進行實例說明,展望了下一代搜索引擎的未來發(fā)展趨勢。