This page introduces radiation.
"What in the world what is radiation?" or
"What types of radiation exist?" and so on.
If you click the left heading of filling your question, you can solve that question.

―Atoms and ions―
　This page contains prerequisites for understanding radiation.
　"What types of radiation exist?"
　Such questions are answered on this page.

―Types of radiation―
　This page discusses types of radiation.
　Maybe you have heard of "alpha rays" and "beta rays".
　This page introduces four types of radiation.

―Characteristics of radiation―
　This page discusses the characteristics of radiation.
　"What is the nature of radiation?"
　Such question are answered on this page and character which is different according to the variety of
　radiation.

―Classification of radiation―
　This page explains the classification of radiation.
　There are various types of radiation and this page classifies the radiation's composition.