Paces and race fitness
Goal pace and training paces
Training paces come from your race fitness today: easy, threshold, half marathon, interval and repetition. They are where you are now, and they move as your race fitness does.
Goal pace is the pace that finishes your goal race in your goal time. On a marathon plan that is your goal marathon pace.
On any other race plan it is your goal time over the race's distance: on a half marathon plan, your goal half marathon pace. You run it in race practice sessions, such as the goal pace part of a long run. Without a goal time, those sessions run at a pace from your race fitness.