Remembrance Sunday, observed on the second Sunday of November, is a solemn day to commemorate military and civilian lives lost in conflicts, honoring their sacrifice and promoting peace, marked by wearing poppies, two-minute silences, and services at war memorials. It originated from Armistice Day (November 11) marking the end of WWI and has expanded to remember all those who died in wars, serving as a time for reflection on the impact of conflict and the importance of unity.