Concept mapping tools allow you or your students to visually depict a system of relationships by creating a map in which nodes represent ideas or facts, and lines or connectors between nodes represent relationships (for example, cause-and-effect relationships, category and sub-category relationships, and so on).
(Resource: University of Waterloo CTL)

Further Reading

• Lucidchart
• A concept map about concept maps

Concept Mapping Tools

• MindMeister (free for up to 3 maps)
• FreeMind (open source)
• Cmap (free)
• Bubbl.us
• Visual Understanding Environment (free)
• Mindomo  (free for up to 3 maps)

Evaluating Concept Maps

• University of Waterloo Centre for Teaching Excellence: Rubric for Assessing Concept Maps
• University of Iowa: Concept Map Rubrics; Assessing & Evaluating Concept Maps