Wartime is the period when a country is fighting a war. During wartime, a nation organizes its resources, people, and industries to support the military effort. Factories that normally make cars might switch to producing tanks or airplanes. Food and materials like metal or rubber might be rationed, meaning families can only buy limited amounts so there's enough for soldiers and equipment.

Life changes significantly during wartime. Young men and women might enlist or be drafted into military service. Families often plant victory gardens to grow their own vegetables. Cities might practice blackout drills, turning off all lights at night so enemy aircraft can't see targets. People buy war bonds to help fund the military, and children collect scrap metal for the war effort.

The word contrasts with peacetime, when a country isn't at war and life follows normal patterns. Some inventions developed for wartime use later become helpful in peacetime: radar, jet engines, and duct tape all came from wartime innovation. Historians often describe major changes by noting what happened during wartime versus peacetime, since wars can reshape societies in lasting ways.