The Justice League, formerly also called the Justice League of America or JLA, is a fictional superhero team that appears in comic books published by DC Comics. First appearing in The Brave and the Bold #28 (February/March 1960), the Justice League originally featured Superman, Batman, Wonder Woman, Flash, Green Lantern, Aquaman, and the Martian Manhunter. The team roster has been rotated throughout the years with characters such as Green Arrow, Captain Atom, Captain Marvel, Black Canary, the Atom, Hawkman, Elongated Man, Red Tornado, Firestorm,Zatanna, Hawkgirl, Cyborg, Vixen, and dozens of others. Sidekicks like Supergirl, Robin, Aquagirl, and Speedy tend to support the main hero or heroine.
The team received its own comic book title in October 1960, when the first issue was published. It would continue to #261 in April 1987, which was the final issue. Throughout the years, various incarnations or subsections of the team have operated as Justice League America, Justice League Dark, Justice League Europe, Justice League International,Justice League Task Force, Justice League Elite, and Extreme Justice.Background
Various comic book series featuring the Justice League have remained generally popular with fans since inception and, in most incarnations, its roster includes DC's most popular characters. The Justice League concept has also been adapted into various other entertainment media, including the classic Saturday morning Super Friends animated series (1973–1986), an unproduced Justice League of America live-action series (for which the pilot film exists), the animated series Justice League(2001–2004) and Justice League Unlimited (2004–2006). A live-action film was in the works in 2008 before being shelved. On June 6, 2012, Warner Bros. announced a new live action Justice League film was in development with Will Beall hired as screenwriter. However, the project is scrapped again. After the success of Man of Steel, a sequel titled, Batman v Superman: Dawn of Justice will serve as a prequel or jumping point for a Justice League film set for a 2017 release. Zack Snyder will direct and Chris Terrio is eyed by Warner Bros. to pen the script who also worked for Dawn of Justice.
Hope that clears everything up.