For example, ozone in our atmosphere absorbs ultraviolet radiation. For example, on Earth the visible window ranges from about 300 to 700 nm, allowing the light we can see with our eyes to pass through the atmosphere.
Stars are approximately blackbodies.
The radiation emitted by blackbodies obeys Wien's Law and the Stefan-Boltzmann Law. For example, energy of motion may change into energy of heat. The intensity of the radiation in such a spectrum changes smoothly from one wavelength to the next. The lines are formed by atoms absorbing light, which lifts their electrons to higher orbits. The shift is an increase in the wavelength if the source and observer move apart and a decrease in the wavelength if the source and observer approach.