previous是前一个的意思，而early则是早期的意思，区别可以从以下例子看出：

I don't like the previous one that you have sent to me, I prefer the early one you have shown to me, I will not mind to pay extra for it. 我不喜欢你寄给我的前一个，我更喜欢你给我看的早期的，我不介意为此多付钱。