This document discusses jails and their role in the corrections system. It covers the origins and evolution of jails, from medieval England to modern America. Jails primarily house those sentenced to one year or less and those awaiting trial. The document examines jail administration, populations, the problems of pretrial detention including bail issues, and challenges in jail management like overcrowding. It also explores the transition to new jail facility designs and trends toward regional jails and strengthened alternatives to incarceration.