This book provides a guide to a rich and fascinating subject: algebraic
curves and how they vary in families. The aim has been to provide a
broad but compact overview of the field which will be accessible to
readers with a modest background in algebraic geometry. Many techniques
including Hilbert schemes, deformation theory, stable reduction,
intersection theory, and geometric invariant theory are developed, with
a focus on examples and applications arising in the study of moduli of
curves.