diff --git a/doc/demo01_hello/3.node.md b/doc/demo01_hello/3.node.md
index 3f058e0..f28c8c9 100644
--- a/doc/demo01_hello/3.node.md
+++ b/doc/demo01_hello/3.node.md
@@ -56,6 +56,7 @@ CTRL + Z ，撤销上一步操作
 
 - 在2D画面中，两个对象如果重叠，谁显示在上面呢？
 - 按照节点的顺序
+- 在数据结构上的专业术语叫树的深度优先遍历，深度优先遍历的顺序就是最后显示的顺序
 
 ![Image text](../demo05_scene_node/image/节点.png)
 ![Image text](../demo05_scene_node/image/节点渲染顺序.png)
diff --git a/doc/demo01_hello/4.resource.md b/doc/demo01_hello/4.sprite.md
similarity index 100%
rename from doc/demo01_hello/4.resource.md
rename to doc/demo01_hello/4.sprite.md