The techniques most extensively used to retrieve interesting data from data-sets are the Skyline and the Top-k queries. Sadly, they are not enough for facing modern problems, so the needing of something more usable and reliable has come. In this survey we are going to explore Flexible Skylines which are proposed to overcame the old fashion techniques' problems by extending the concept of dominance. After, we are going to compare this approach with the old and new ones evaluating pros and cons. Finally, we will see some interesting applications.