What does spectral line mean? What are emission and absorption lines?

Definition on Wikipedia: A spectral line is a dark or bright line in an otherwise uniform and continuous spectrum, resulting from emission or absorption of light in a narrow frequency range, compared with the nearby frequencies. Spectral lines are often used to identify atoms and molecules. These “fingerprints” can be compared to the previously collected … Read moreWhat does spectral line mean? What are emission and absorption lines?