R-tree is a dynamic index tree of space search. Its structure use multi-dimensional region to express spatial data object. R-tree is a valid way to visit rectangle.

树是空间搜索的动态索引树，它的结构是利用多个维中的区间来表示空间数据对象，它是矩形访问的一种有效方法。

youdao

I've been using the blackboard a little ad hoc here, but suppose I neaten things up here now and present this rectangle is let's say R RAM, the memory inside of your computer.

我在这里特别地使用这块黑板，假如我整理这些东西，把它们呈现,这个长方形，假如说就是内存，你电脑的内存。

哈佛公开课 - 计算机科学课程节选