Question

what is orbital ?

Answer 1

orbital is nothing ...An orbit is a regular, repeating path that an object in space takes around another one...

Answer 2

It depends on context. I will assume you mean orbitals of electrons on atoms. They are rings where it is most likely to find an atom's electron, but are often treated as areas where electron groups, representing energy levels, are said to reside all the time.
Ghazi's explanation is valid in most cases as well though.

Answer 3

It is the probability cloud where there is a chance of finding an electron