electromagnetic spectrum 同 electromagnetic waves 係唔係一様meanin

A [spectrum] generally refer to a distribution of frequency (or wavelength). For example, a [light spectrum] refers to the distribution of colours in the visible light range. A [gamma ray spectrum] refers to the distribution of gamma ray energy (which is directly related to frequency) of a gamma ray source, e.g. a radionuclide.

Hence, [electromagnetic spectrum] refers to the distribution of frequency of the concerned electromagnetic waves (EM waves). It could be the spectrum of a particular range of EM wave, e.g. the spectrum of ultra-violet EM wave, or the spectrum of broadcasting EM waves.

Electromagnetic waves refer to the NATURE of the wave, as constrast to mechanical waves like sound waves or water waves, that the (EM) waves travel by changing electric and magnetic field components.

electromagnetic spectrum係電磁譜,包含哂所有嘅electromagnetic waves電磁波.即係electromagnetic waves係subset of electromagnetic spectrum.