In this last chapter of the book, we discuss several culminating topics, tying together our prior developments of affine, projective, and quasiprojective varieties. In the first three sections, we further develop the parallelism between the affine and quasiprojective settings, extending the notions of dimension and smoothness to the quasiprojective setting. In some sense, these extensions require little additional work: dimension and smoothness are local properties, and since every quasiprojective variety is locally affine, our understanding of dimension and smoothness for affine varieties can be imported directly to the quasiprojective context.