CBT is a form of psychotherapy that focuses on thoughts and behaviors. The goal is to find and challenge the distorted or unhelpful thinking patterns, the respective inaccurate beliefs, and the consequential maladaptive behaviors, and to move towards positive and healthy thoughts and behaviors.
REBT is a form of psychotherapy that focuses on problems/issues as they relate to emotions, thoughts, and behaviors. The goal is similar to CBT but focuses more on the emotional impact to our thoughts and behaviors.
CBT: developed by Aaron Beck
REBT: developed by Albert Ellis