The role of corrective feedback (CF) in the L2 learning process has for decades remained a dominant issue in the (I)SLA strands of research, albeit some overlapping between these two contexts. Indeed, there are several cognitive theoretical underpinnings cited by empirical CF studies to account for the role or lack thereof of CF in the L2 learning process, for example, the Monitor Model (Krashen, 1982), the Interaction Hypothesis (Long, 1996), the Noticing Hypothesis (Schmidt, 1990), the Output Hypothesis (Swain, 2005), Skill Acquisition Theory (DeKeyser, 2015), and the Model of the L2 learning process in ISLA (Leow, 2015), be it oral, written, or computerized or digital. This chapter (1) traces the early roots of CF, (2) presents a coarse-grained theoretical feedback processing framework to discuss the cognitive theoretical underpinnings postulated to account for the role of CF in L2 development, (3) provides a list of cognitive processes assumed to play a role during CF appropriation, and (4) reports on each theoretical underpinning followed by a commentary on their ability to account for the role of CF in L2 development.