ANZAC Day marks the anniversary of the first major military action fought by Australian and New Zealand forces during the First World War. On the 25th of April 1915, Australian and New Zealand soldiers formed part of the allied expedition that set out to capture the Gallipoli peninsula. The Anzacs landed on Gallipoli and met fierce resistance from the Ottoman Turkish defenders. Their plan to knock Türkiye out of the war quickly became a stalemate and the campaign dragged on for eight months. 

At the end of 1915, the allied forces were evacuated. Both sides suffered heavy casualties and endured great hardships. Over 8,000 Australian soldiers were killed. 

The meaning of Anzac Day today includes the remembrance of all Australians killed in military operations. Commemorative services are held at war memorials at dawn – the time of the original landing in Gallipoli. Later in the day, current and former servicemen and women meet to take part in marches.

Source: https://www.army.gov.au/about-us/history-research/traditions/anzac-day