Final answer:
The boy band formed by Simon Cowell on July 23rd, 2010, during "The X Factor" was called One Direction, and they had the best-selling album worldwide in 2013 titled "Midnight Memories."
Step-by-step explanation:
On July 23rd, 2010, Simon Cowell formed the boy band One Direction on the British television show, "The X Factor." Although they finished in third place, the group became extremely successful, and their album "Midnight Memories" was the best-selling album worldwide in 2013. "One Direction" is a British-Irish boy band that was formed on the seventh series of the British television music competition "The X Factor" in 2010. The group consisted of five members: Niall Horan, Zayn Malik, Liam Payne, Harry Styles, and Louis Tomlinson. Although the group finished in third place on the show, they quickly gained a massive fan base and achieved unparalleled success in the music industry.