What is the difference between CharSequence[] and a String[]?

Question

What is the difference between CharSequence[] and String[]?

Answer 1

Here is my diagram showing how String is a one of several concrete classes implementing the CharSequence interface.

In particular, StringBuilder is commonly used as a faster alternative to concatenation String objects with the + operator, where thread-safety is not needed.

The square brackets means an array. So, String[] is an array of String objects, and CharSequence[] is an array of objects that may or may not be String objects but definitely are objects implementing the CharSequence interface.

See my Answer here and my Answer here for much more discussion.