WW1 ended at 11 o'clock on the morning of the 11th day of the 11th month of 1918.
Armistice Day is on 11 November and is also known as Remembrance Day. It marks the day World War One ended, at 11am on the 11th day of the 11th month, in 1918.
A two-minute silence is held at 11am to remember the people who have died in wars. There is also Remembrance Sunday every year, which falls on the second Sunday in November. On this day, there are usually ceremonies at war memorials, cenotaphs and churches throughout the country, as well as abroad.
The Royal Family and top politicians gather at The Cenotaph in Whitehall, London, for a memorial service. The anniversary is used to remember all the people who have died in wars - not just World War One. This includes World War Two, the Falklands War, the Gulf War, and conflicts in Afghanistan and Iraq.