I would describe integration as remembering and feeling.
When the brain gets stressed beyond regular coping methods, it buries information and stores it until it’s ready (or safe) to process it. When a sense of safety is found, integration then happens. The stressful event is remembered and processed. Integration requires safety, patience, strength, and time.
Integration is the polar opposite of dissociation. Dissociation can be one of them most troubling symptom of PTSD or C-PTSD. Dissociation links directly to the past. It happens when the brain gets stressed beyond it’s ability to process.
Integration organizes all the different aspects of a person. Personality and self unify into one.
Integration happens when the sludge of trauma disappears giving way to establishing a more rounded personality.