To pay their respects on Remembrance Day, people wear poppies of different colours to honour the sacrifices made by soldiers and those affected by war.
The red poppy is the oldest and most popular choice - whilst others wear white, purple, and black ones to symbolise their causes.
The emergence of a rainbow poppy - to honour LGBT soldiers - has divided opinion.
A viral Twitter rant argues that soldiers should be remembered for one day "without it being about sexuality".
However, an activist says that the sacrifices made from the LGBT community during different conflicts have been ignored - and they should be honoured.
The Claim
A Twitter rant about rainbow poppies has went viral ahead of Remembrance Day, The Sun reports.
The user called Cassie attacked the symbol commemorating LGBT soldiers, saying that it has gone "too far".
She tweeted : "Why am I seeing rainbow poppies being made?
"Not to be rude but there is a whole month dedicated to the LGBT community.
"Can the heroes that fought for our country have the ONE day to be remembered without it being about sexuality?
"It's going too far now."
Other Twitter users backed her poppy stance, with the post receiving almost 54,000 likes since it was posted on Monday.
The Counterclaim
However, Peter Tatchell believes that LGBT military personnel should be honoured on Remembrance Day.
The LGBT campaigner said that their sacrifice during the Second World War has been ignored over the years.
He told Yahoo News UK : "On Remembrance Sunday, it is quite right that we honour all those who fought for freedom against the Nazis and other tyrannies, including black and LGBT military personnel...
"For decades, the Royal British Legion refused to acknowledge that any LGBT people risked and gave their lives to defend democracy."
An estimated 200,000 LGBT soldiers and sailors served during the Second World War.
Tatchell added: "On Remembrance Sunday, I will be joining a gay veteran to lay a pink triangle poppy wreath at the Cenotaph.
"Like thousands of others, he was jailed and booted out of the armed forces for no other reason than his sexuality.
"The military has a shameful record of homophobic witch-hunts and should make a public apology to the personnel they mistreated."
The Facts
The red poppy is the original symbol of remembrance created by the Royal British Legion nearly 100 years ago.
According to the charity , wearing the red poppy is "a show of support for the service and sacrifice of our Armed Forces, veterans and families".
It pays respect the lives lost in active service - from the beginning of the First World War to current conflicts.
The Royal British Legion updated its definition of the remembrance symbol ahead of this year's Poppy Appeal. The red poppy will also pay tribute to civilian victims of war and "acts of terrorism" .
The charity said that it has not altered its red two petal poppy or issued a rainbow poppy. A spokesman added that the red poppy "recognises the service and sacrifice of people from all communities", including the LGBT community.
It is hoping to raise over £50m in this year's Poppy Appeal. It will see 40,000 collectors raise money from more than 40m paper poppies , 750,000 remembrance crosses, half a million other poppies, and 100,000 wreaths and sprays.
There are different colours of poppies sold and worn by different organisations.
The white poppy was designed by the Co-operative Women's Guild in 1933, and it was adopted by the Peace Pledge Union (PPU) in 1936. It is used as a symbol of pacifism and a commitment to peace.
The PPU explains: "There are three elements to the meaning of white poppies: they represent remembrance for all victims of war, a commitment to peace, and a challenge to attempts to glamorise or celebrate war."
Since 2014, the PPU has sold around 100,000 white poppies every year .
There are also purple puppies, which are worn to pay tribute to the animals that have been victims of war.
Animals - such as horses, dogs, and pigeons - were drafted into the war effort. It is estimated that eight million horses and donkeys died during the First World War.
The purple poppy was first used by Animal Aid, the oldest and largest animal rights group in the UK, in 2006. The charity swapped the purple poppy for an enamel purple paw badge in 2015.
Animal Aid's co-founder Andrew Tyler explained their decision, saying that the group's aim was to " make it clear that animals used in warfare are indeed victims, not heroes ".
Another purple poppy campaign was created by Murphy’s Army, a West Yorkshire charity for missing animals, in 2016.
A black poppy is also available to commemorate black, African, and Caribbean soldiers and civilians affected by war.
The Black Poppy Rose was launched in 2010 by Selena Carty to symbolise the contributions that the communities made to various wars since the 16th century.
