What is Conjugated system, chromophore, absorption maximum?

A conjugated system is a chain of atoms each carrying a $p$ orbital in a $\pi$ system, as in alternating double and single bonds (buta-1,3-diene, benzene). The group of atoms responsible for an absorption is its chromophore; the wavelength at which its absorbance is greatest is the absorption maximum, $\lambda_{\max}$.