Modelling the chemical evolution
  Advanced observational facilities allow to trace back the chemical evolution
of the Universe, on the one hand, from local objects of different ages and,
secondly, by direct observations of redshifted objects. The chemical enrichment
serves as one of the cornerstones of cosmological evolution. In order to
understand this chemical evolution in morphologically different astrophysical
objects models are constructed based on analytical descriptions or numerical
methods. For the comparison of their chemical issues, as there are element
abundances, gradients, and ratios, with observations not only the present-day
values are used but also their temporal evolution from the first era of metal
enrichment. Here we will provide some insight into basics of chemical evolution
models, highlight advancements, and discuss a few applications.
