These boxes and bullet graphic organizers aid in demonstrating connections between the main concept and other information. Concepts are usually represented in circles or boxes, and arrows connect them. Cross-links are another feature of boxes and bullet graphic organizers that show relationships between sub-ideas in different segments of the concept map. The main idea web begins with a central idea and expands into related ideas and details (or sub-ideas). This type of graphic organizer, also known as spider or semantic maps, is primarily used for brainstorming while generating ideas for planning or writing purposes.