Actinic ray and Electromagnetic radiation

Actinic ray noun - Electromagnetic radiation that can produce photochemical reactions.

Electromagnetic radiation and actinic ray are semantically related. In some cases you can use "Electromagnetic radiation" instead a noun phrase "Actinic ray".

Electromagnetic radiation noun - Radiation consisting of waves of energy associated with electric and magnetic fields resulting from the acceleration of an electric charge.

Actinic ray and electromagnetic radiation are semantically related. Sometimes you can replace phrase "Actinic ray" with "Electromagnetic radiation", this phrases are similar.