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In this talk, I will talk about several interesting and peculiar aspects of the photon in high energy scatterings. First, I will review the history of Weizsacker-Williams photon distribution in a relativistic moving charged particle in the so-called equivalent photon approximation (EPA), and discuss the extension of this method towards the photon Wigner distribution. These methods can be applied to the dilepton productions recently measured by STAR, ATLAS and CMS collaborations. In the end, I will also mention the rich QCD structure of the photon and its implication on the collective phenomenon at the future EIC.