[en] This paper will be an overview presenting some of the basic atomic collisions processes (gas phase) which are fundamental to production and destruction of H^-(D^-). More detailed discussions of the most important processes will be left to other papers at this Symposium, and primarily new results since the 1977 Symposium will be discussed. Recent results provide insight into mechanisms responsible for the high H^-(D^-) ion fractions in hydrogen gas discharges, and the ion-atom collision processes important for double capture negative ion sources are better understood than in 1977