The topic of chemical evolution of galaxies tends to frighten off even the bravest of astronomers. Some of that can be attributed to uncertainties in abundances determinations (which I hoped that I have addressed above), but I think there is another factor. Most of us, once we have learned a little bit about the subject, acknowledge that there are a large number of factors which affect the chemical evolution of galaxies. This often gives rise to a reaction of surrender - after all, if there are so many free parameters, how can one possibly make progress? I would respond, if ones goals are modest, I think that there is a great deal of potential for progress. The purpose of this next section is to lay out some of the simplest ideas concerning chemical evolution.