Those who use social media may have happened across the term 'GOAT' being used in association with the best sports starts in the world.
Roger Federer, Usain Bolt, Tom Brady and LeBron James are just some of the names that have been branded the GOAT.
The likes of Lionel Messi and Cristiano Ronaldo are also regularly present on similar lists of elite-level athletes.
So what does GOAT mean and who is the GOAT? Goal takes a look.
What does GOAT mean?
GOAT (or G.O.A.T.) is an acronym which stands for 'greatest of all time'. It is a tag which is reserved for the individual who is deemed to be the undisputed master of their sport.
As well as exceptional talent, in order to be considered the GOAT, the individual must also maintain a consistent high level of achievement.
While it has been in use for a long time, the term was popularised in the 20th century by heavyweight boxing champion Muhammad Ali, who, in 1964, declared himself "the greatest" after defeating Sonny Liston.
It subsequently became a moniker for Ali throughout his career and he famously revisited the catchphrase after defeating George Foreman by knockout, against the odds, in 1974.
"Everybody stop talking now. Attention! I told you, all of my critics, I told you all that I was the greatest of all time when I beat Sonny Liston," Ali said following the fight dubbed the 'Rumble in the Jungle'.
"I told you today, I’m still the greatest of all time. Never again defeat me. Never again say that I’m going to be defeated. Never again make me the underdog until I’m about 50 years old. Then you might get me."
As the name suggests, the GOAT is not only deemed to be better than all of their contemporaries, but better than everyone who has gone before them as well.
Who is the GOAT in football?
Football's GOAT is a matter of continuous debate within the community, but the consensus in recent years has narrowed the question down to one of two players: Ronaldo or Messi.
The very nature of the game means that there is no hard and fast method by which to measure who exactly is the greatest of all time, but that reality hasn't stopped the arguments.
Both Ronaldo and Messi have won the Ballon d'Or - given to the player who is considered the best in the world - on five occasions, which is more than any other player.
Messi edges things when it comes to the European Golden Shoe, which he has scooped five times to Ronaldo's four, and they each have four Champions League winners' medals.
The gauge for discerning who the GOAT is can vary, but some have highlighted Ronaldo's ability to excel in a number of different countries as a reason for placing him ahead of the Argentine.
As well as that, the Portugal captain has lifted major honours with his country (winning the European Championship in 2016), a feat Messi has yet to achieve at senior level with Argentina (he has won an Olympic gold medal and the Under-20 World Cup).
Both players spurred each other on and embraced the tag of GOAT, with Messi sheepishly posing with a live goat in an edition of PAPER Magazine, while Ronaldo briefly fashioned a goatee at the 2018 World Cup.
"The rivalry with Cristiano was very healthy and good for the fans," the Barcelona captain told Marca following Ronaldo's switch to Juventus.
Other GOATs in football history
The dominance of Messi and Ronaldo over the past decade has reduced other iconic football figures to mere afterthoughts, but plenty still lay claim to the title of GOAT.
Messi's compatriot Diego Maradona, a World Cup winner with Argentina in 1986 who shone at Barcelona and Napoli, is one example, though interestingly, Maradona considers Messi to be his heir and has proclaimed the Rosario native to be the greatest.
Netherlands and Barcelona legend Johan Cruyff is another individual who is considered by many to be the greatest footballer of all time. He won three Ballons d'Or during his career and was the creative force which drove Ajax on to three European Cup triumphs in the early 1970s. Cruyff's influence is still felt at Barcelona to this day, with the Dutchman dubbed El Salvador, or The Saviour, by fans of the Catalan club.
Others who have been declared the greatest include Pele, Ronaldo (O Fenomeno), Alfredo Di Stefano, Zinedine Zidane, Michel Platini and Franz Beckenbauer. More recent candidates include the likes of Andres Iniesta, Luka Modric, Xavi and Ronaldinho.
Future football GOATs?
When Messi and Ronaldo eventually hang up their boots, a void will emerge into which a pretender will step, and already a few stars are being touted as their successors.
Neymar's PSG team-mate - and World Cup winner - Kylian Mbappe cemented his status as one of the best young players in the world in 2018, but he will have to maintain his high standards in order to earn the tag of GOAT.
Chelsea playmaker Eden Hazard, Liverpool's Mohamed Salah and Atletico Madrid forward Antoine Griezmann have catapulted themselves into the vicinity of Ronaldo and Messi, but the feeling is that they will all have to raise their games in order to reach the same level.
The aforementioned stars have been earmarked, but there is always a chance that some phenomenon will emerge from the fog of obscurity and exceed both Messi and Ronaldo. That would require a gargantuan effort and may seem highly unlikely at this point.