Top "Kleene-star" questions

In computation theory, the kleene star (*) is a regular operation all regular languages are closed under.

An infinite language can't be regular? What is a finite language?

I read this in a book on computability: (Kleene's Theorem) A language is regular if and only if it can …

regular-language finite-automata formal-languages computability kleene-star
Automata Regular expression - difference between concatenation & union

What is the difference between the following regular expressions? (a U b)* and (ab)* Difference between union and concatenation ? which …

regex kleene-star