Differences between Fail-fast and Fail-safe iterators are as

follows:

Fail-fast iterator throws ConcurrentModificationException. But

Fail-safe iterator does not throw this exception.

Fail-fast iterator does not clone the original collection. Fail-safe

iterator creates a copy of the original collection of objects.

A Fail-fast iterator tries to immediately throw Exception when it

encounters failure. A Fail-safe Iterator works on a copy of

collection instead of original collection.

https://www.javatpoint.com/fail-fast-and-fail-safe-iterator-in-java#:~:text=The%20Java%20Collection%20supports%20two,in%20case%20of%20a%20failure.