Its item number is

One example is Google's search engine, which is partly guided by the number of clicks on an item to help determine its relevance to a search query.

其中一个例子是谷歌的搜索引擎，该引擎部分根据一个对象被点击的次数来帮助决定该对象对搜寻的相关度。

Next to each item is a number indicating its location within the collection.

每项旁边的数字指示该项在集合中的位置。