Complex sentence: Concept maps are rather similar to topic maps (in that both allow to connect concepts or topics via graphs), while both can be contrasted with the similar idea of mind mapping, which is often restricted to radial hierarchies and tree structures.
Split into simpler sentences: Concept maps are rather similar to topic maps in that both allow to connect concepts or topics via graphs. Both concept maps and topic maps can be contrasted with mind mapping, which is often restricted to radial hierarchies and tree structures.