online shopping是网上购物的意思，而shop online则是在网上购物的意思，区别可以从以下例子看出：
During covid 19 pandemic， online shopping is crucial， we should learn how to shop online. 在covid 19大流行期间，网上购物至关重要，我们应该学习如何网上购物。
区别就是online shopping为名词而shop online为动词，具体的不同如下
online shopping中文意思是n，网络购物，网上购物
Online shopping is a new way of shopping.
shop online中文意思是在线购物，网上购物
In recent years， there is a growing tendency for people to shop online， and most people more or less have the experience of shopping online.
