Using Spring Security Annotations isFullyAuthenticated v/s hasRole

Being new to spring security annotations, I am not able to understand the real difference between the below two lines. Does it mean that hasRole implicitly checks for authentication?

-    @PreAuthorize("isFullyAuthenticated() and hasRole('activateUser')")
+    @PreAuthorize("hasRole('activateUser')")

void activateUser(String username);

As per spring documentation,

isFullyAuthenticated()  Returns true if the user is not an anonymous or a remember-me user