One Direction were formed in 2010. Originally they never intended to become a boy band at all. The five individual artists - Harry Styles, Louis Tomlinson, Liam Payne, Zayn Malik and Niall Horan - each hoped to appear solo on The X Factor. However, none of them was considered good enough in the early stages to be put in the 'boys' category' and that could have been the end of the story.
Then one of the show's judges at the time, Nicole Sherzinger, suggested that if they all got together they might have a better chance as a boy band. They did so in July of the same year and entered in the 'groups' category instead. During the two weeks that they spent getting acquainted and rehearsing, Harry Styles chose the name of One Direction, and the new band decided to perform a version of Ednaswap's song Torn.
You can learn more about the history of One Direction here.