Mind map basic elements are:
"1" main topic, the title or main idea of this mind map.
"2" topic, the subtitle of this mind map.
"3" subtopic, a topic can include many subtopics; and a subtopic can also include it's own subtopics.
"4" boundary, to draw a boundary around a topic and it's all subtopics to emphasize them.
"5" relationship, a line with one or two head connect two topics , to indicate that they are related.