Adidas supplies the official ball for FIFA World Cup association football. Since the 1970 tournament, FIFA World Cup finals have used specially designed Adidas match balls, making the partnership one of the longest-running equipment relationships in major sport.
The first Adidas World Cup ball was the Telstar, used at the 1970 tournament in Mexico. Its black-and-white pattern was designed to remain visible on television, especially on the era’s mostly monochrome broadcasts. Later balls introduced major changes in panel construction, surface texture, water resistance, and aerodynamic behavior.
The answer is sometimes shortened to “soccer” in American English, but “football” is the standard international name for the sport governed by FIFA. Adidas also supplies balls for other competitions, including the UEFA Champions League, so the question refers specifically to the FIFA World Cup rather than every football tournament.