IT'S been 75 years since the Allied invasion of Normandy on June 6, 1944, with nations remembering the sacrifices made on D-Day.
But as we commemorate the brave heroes of Operation Overlord, what does D-Day mean?
What does the D in D-Day mean?
We all know the term D-Day, but do we know where the phrase comes from?
The D actually stands for Day, meaning it's the day on which a military operation will start.
Nowadays it's not just used as a military term but also for any important day, challenge, or day of significance, such as one marking an important event or goal.
However, when people say D-Day, it's most recognisable as the invasion of Allied troops in Normandy during World War II.
What happened on D-Day, June 6, 1944?
On June 6, 1944, the Allied Forces of Britain, America, Canada, and France attacked German forces on the coast of Normandy, France.
With a huge force of over 150,000 soldiers, the Allies attacked and gained a victory that became the turning point for World War II in Europe.
Bad weather almost caused the attack, scheduled for June 5, to be postponed, but as the German's weren't expecting it for the same reason, they were unprepared when the attack came.
An invasion force of over 6,000 ships carrying troops, weapons, tanks, and equipment approached the beaches of Normandy.
By the end of D-Day over 150,000 troops had landed in Normandy - with 4,413 dying on D-Day alone.
They pushed their way inland allowing more troops to land over the next several days.
Within five days 326,547 troops and 104,428 tons of supplies had landed on the beaches.
By June 17 over half a million Allied troops had arrived and they began to push the Germans out of France.
The attack, known as Operation Overlord, included a combined naval, air and land assault on Nazi-occupied France.
The landings were followed by the 76 day Battle of Normandy, with a total of 210,000 Allied casualties including American, British and Canadian.
They were backed up by Australian, Belgian, Czech, Dutch, French, Greek, New Zealand, Norwegian, Rhodesian and Polish naval, air or ground support.
Where are the Normandy beaches?
The Normandy beaches are located in northern France.
Early on June 6, 1944, Allied airborne forces parachuted into drop zones across northern France, followed by ground troops who landed across the five targeted beaches.
These beaches were code-named Utah, Omaha, Gold, Juno and Sword, and spread across a 50-mile stretch of northern Normandy.
Through these strategic landings, the Allies were able to get a foothold along the coast and advance into France for the first time since 1940.
Why was D-Day important and when did WWII end?
The invasion of northern France in 1944 was the most significant victory of the Western Allies in the Second World War.
American, British and Canadian forces established a foothold on the shores of Normandy, and, after a protracted and costly campaign to reinforce their gains, broke out into the French interior and began a headlong advance.
The German Army suffered a catastrophic defeat they couldn't recover from.
World War 2, which had started on September 1, 1939, finally ended on September 2, 1945, over a year after the D-Day landings.
How was the 75th anniversary marked in 2019?
On June 6, 2019, a lone piper played at 6.25am on Arromanches beach, marking the moment the first British soldier stormed the beaches of Normandy.
Theresa May and French President Emmanuel Macron attended a memorial inauguration at Normandy and veterans will join them for a cathedral service in Bayeux.
US President Donald Trump's state visit to the UK coincides with the 75th anniversary of the D-Day landings, on June 6.
Prince William attended a special D-Day Remembrance Service at The National Memorial Arboretum, Staffordshire, and Prince Harry met Chelsea Pensioners.
In Portsmouth, following President Donald Trump's visit on Wednesday, a veteran's parade will take place before a memorial service at the city's D-Day Stone.
Trump joined Theresa May, the Queen, Prince Charles, D-Day veterans and other world leaders in D-Day commemorations on June 5.
The event on Southsea Common in the Hampshire port city included an hour-long production telling the story of the invasion with testimony from veterans, theatrical performances and live music, as well as a flypast of the Red Arrows and Spitfires.
On the evening of June 5, Normandy veterans left Portsmouth to follow the route across the English Channel they took in choppy waters in 1944 as part of the biggest sea invasion in history.
MORE ON D-DAY
In the middle of the Channel, at around 8pm, a fleet of Royal Navy ships sailed past MV Boudicca while the RAF flew overhead.
Other events included a formation flight of Dakotas at Duxford Airfield, Cambridgeshire.
Veterans met Prince Charles and Camilla after a remembrance service at the war cemetery at Bayeux, where the bodies of 1,800 British and Commonwealth servicemen lie.
Remembrance services were also being held at Bayeux Cathedral and the Bayeux War Cemetery in Normandy which were open to the public.
The President laid a wreath at the Tomb of the Unknown Warrior in Westminster Abbey on June 3, ahead of the 75th anniversary of D-Day.