What is the difference between regulars and militia?

Regulars are professional soldiers who are part of a standing army, trained and equipped for full-time military service. In contrast, militia refers to civilian volunteers who are organized for military service, often part-time, and typically called upon in times of emergency or for local defense. Regulars operate under formal military command and structure, while militia members may have varying levels of training and organization. Additionally, militias often serve specific local or regional purposes, whereas regulars are deployed for national defense and broader military operations.