What is the difference between chronic PTSD and complex PTSD?

Complex PTSD (C-PTSD) is a psychological disorder that results from suffering prolonged repeated interpersonal trauma. Examples of such trauma include childhood sexual abuse, chronic emotional or physical abuse, chronic domestic violence etc. I.e. C-PTSD arises from suffering multiple episodes of interpersonal trauma while PTSD arises from witnessing or experiencing a single traumatic event. Chronic PTSD merely means the PTSD symptoms have lasted for more than 6 months.