What are nested comments?

Answer 1

A nested comment is a comment inside another comment. In Java you can't nest a multiline comment into another multiline comment, however you can nest a single line comment into a multiline comment (but does this make sense?)

/*
This is a comment
// this is a nested comment
This is another comment
*/

Answer 2

Nested comments are like this

/* multi line comment
//single line comment
*/