[Vocabulary] the difference between words

[pffert]

I saw these words on the introduction book.And "caution" and "alert" mean warning,I want to know they are same?Is there any differences between "caution" and "alert"

 

[bhaisahab]

I saw these words on the introduction book.And "caution" and "alert" mean warning,I want to know they are same?Is there any differences between "caution" and "alert"

Have you looked them up in a dictionary?