This thesis provides an improved understanding of Sn spectroscopy through the identification of spectral lines in both lowly and highly charged tin ions, and applying this knowledge to investigate relevant Sn plasmas. Charge-state-resolved measurements on highly charged tin ions, which emit brightly in the EUV regime, are performed at the Max-Planck-Institut für Kernphysik in Heidelberg, Germany. Spectral measurements in the optical and EUV range on laser-produced plasmas have been performed in the EUV Plasma Processes group at the Advanced Research Center for Nanolithography in Amsterdam.