Compare reference and thematic maps

Reference maps are used to show locations of many types of features (e.g. cities in relation to highways). They often use conventional colours and symbols to represent a great variety of topics. Thematic maps on the other hand usually present only one topic or one specific subject area.

radiative zone

explanation    

radiative zone is the layer of the sun which energy is transferred away from the core by radiation. although, the core is the only part of the sun that produces an appreciable amount of heat through fusion. in fact, 99% of the energy produced by the sun takes place within 24% of the sun's radius.