In this talk, I will introduce quantum correlations, one of the key aspects of quantum information theory, starting with the seminal example of Bell non-locality. I will review Bell’s theorem, which shows how quantum mechanics cannot be simulated classically. Generalizations of Bell non-locality and other types of quantum correlations will be outlined. Experimental research and applications of quantum correlations will be briefly discussed, with a focus on quantum communication using quantum optics and light-matter interaction.