In the case of Sebring, most people use the term to refer to the cluster of corners, 3/4/5. Hard left hand turn into turn three, slight right is turn 4, with a high speed turn to the left at turn 5. It is unusual to hear people talk about this set of corners as individual corners, instead you take it all as one "complex." The way you setup for three affects how you take turn 4, and ultimately your exit speed for turn 5. That is why I did not put a space between my description for turn 3 and turn 5.