The recent discovery of "giant" electrostrictors has re-ignited the interest in electrostriction, an electromechanical coupling existing in all dielectrics but overshadowed by its linear counterpart: piezoelectricity. In this review, after a reminder of "classical" electrostriction, we propose a definition of "giant" electrostriction based on two empirical relations ("Newnham" relation and one we posit). From this definition, we review previous reports on "giant" electrostrictors, to assess their nature. Focusing on the ones satisfying our definition, we compare their performances and characteristics. We also identify some of the hurdles to overcome before their adoption in the wide range of electromechanical applications, despite their fundamental and applicative interests.