Hi, I hope it is not too late to answer your question. It is an excellent question, so good that I would think you are a scientist studying CMEs and flares! A flare refers to a sudden brightening of a local region at low corona close to the solar surface. A CME refers to a blob of material and/or magnetic structure that erupts and leaves the Sun. Almost all large flares have their own companion CMEs from the same region. Many small flares do not have observable CMEs, which could mean no CME or too small to be seen. The relationship between flares and CMEs is an outstanding question still. Perhaps they are just two different appearances of a same solar activity. Yan