兩者意思不同，以下內容摘自《英語常用詞多用途詞典》（金盾出版社），供參考：

later[5leItE] a.

1.以后的，晚些時候的：

We can settle on the price at a later date. 我們可以過幾天再商定價格。

2.后面的：

We will discuss this in detail in a later chapter. 我們將在以后的一章中對這一點作詳細的探討。

3.末期的，后期的，晚年的：

His later stories are not interesting because of their poverty of imagination. 他后來寫的故事因為缺乏想象力而枯燥乏味。

In her later years she gave herself over to writing full-time. 她晚年專事寫作。

latter[5lAtE] a.

1.后者的：

I have studied English and Japanese; the former language I speak very well, but the latter one only a little. 我學英語和日語；前者我可講得很好，而后者只能講一點。

2.后一半的，末了的：

He spent the latter years of his life in France. 他在法國度過了他的后半生。

I disliked the latter part of the book. 我不喜歡這本書的后半部。