Computer support offers versatile opportunities for learning together at a distance as well as for colocated scenarios of collaborative learning, in which learners construct arguments, share knowledge, and jointly produce task solutions themselves. In this chapter, we explore different computer-mediated and co-present forms of computer-supported collaborative learning (CSCL). We will discuss both the potential and the problems of CSCL. Finally, we will show how current instructional approaches aim to overcome CSCL problems to realize its full potential.