The particle correlations at small relative velocities are sensitive to the space—time characteristics of the production processes on a femtometer scale owing to the effects of quantum statistics and finalstate interaction. Though the final—state interaction complicates the correlation analysis, it is an important source of information allowing for coalescence femtoscopy, correlation femtoscopy with unlike particles including access to the relative space—time asymmetries in particle production, and a study of strong interactions between specific particles. I will briefly discuss the history and basics of correlation femtoscopy, some of the recent results from femtoscopy of relativistic heavy-ion collisions, and their consequences.