Short answers, pulled from the story.
The four stars above Uruguay's football crest each represent one FIFA-recognized world championship: the 1924 Paris Olympics, the 1928 Amsterdam Olympics, the 1930 FIFA World Cup, and the 1950 FIFA World Cup. FIFA officially recognizes all four as senior, non-amateur world titles.
Uruguay carries four stars because FIFA recognizes them as four-time world champions. Two titles came from the 1924 and 1928 Olympic football tournaments, which FIFA administered and opened to professional players, and two came from the 1930 and 1950 FIFA World Cups.
Uruguay first added four stars to their football crest in 1992, following approval at the FIFA Congress in Zürich. The request was put forward by Uruguayan football historian and journalist Atilio Garrido. The four stars have appeared on Uruguay's jersey at every FIFA World Cup since 2002.
Atilio Garrido, a Uruguayan football historian and journalist, argued Uruguay's case for four stars at the 1992 FIFA Congress in Zürich. Garrido presented official AUF documents from 1925 and 1929 that had registered Uruguay as world football champions after the 1924 and 1928 Olympic titles. FIFA accepted his argument.
In 2021, a leaked email from Puma revealed that a FIFA employee had asked the kit manufacturer to remove two of Uruguay's four stars before a World Cup qualifier. The AUF organized a formal defence using football historians and primary documents, and FIFA retracted the request. Uruguay wore all four stars against Colombia on the 7th of October 2021.
FIFA officially recognizes Uruguay's 1924 and 1928 Olympic titles as open world championships equivalent to the FIFA World Cup. Both tournaments were administered by FIFA alongside the French and Dutch football associations, were open to professional players, and had only minor IOC involvement. This recognition was formally registered at the 1992 FIFA Congress and reaffirmed on FIFA's official website in February 2023.