Even though Albert Ellis was more of a therapist than a theorist, his interpretation of cognitive theory has gained a great deal of notability over the past twenty plus years. On the surface, his model is quite simple and often described as the A-B-C process.
According to Ellis, we experience Activating Events (A) everyday that prompt us to look at, interpret, or otherwise think about what is occurring. Our interpretation of these events result in specific Beliefs (B) about the event, the world and our role in the event. Once we develop this belief, we experience Emotional Consequences (E) based solely on our belief.