The Justice League has its main characters - Superman, Batman, Wonderwoman, Aquaman, etc. Then there's the "Justice League of America". Why are there two teams with such similar names? Does it mean that the Justice League is international, and the JLA is only for America?
Nothing: functionally there is no difference in the comic save for the removal of the "of America." The Justice League of America was the comic's working title since its inception in 1960. As the comic was an homage to the earlier Golden Age Justice Society of America, it seemed appropriate to keep the titles similar.
The first appearance of the Justice League in Brave and the Bold #28 (1960)
The Justice League, also known as the Justice League of America (JLA), is a fictional superhero team appearing in American comic books published by DC Comics. The Justice League was conceived by writer Gardner Fox, and first appeared in The Brave and the Bold #28 (Feb.-March 1960).
The team is an assemblage of superheroes who join together as the Justice League. The seven original members were Batman, Aquaman, the Flash, Green Lantern, Martian Manhunter, Superman, and Wonder Woman. The team roster has rotated throughout the years, consisting of many superheroes from the DC Universe. The Justice League received its own comic book title called Justice League of America in October 1960.
As the Justice League grew more popular it eventually evolved into the Justice League International. This title was technically a misnomer since the Justice League of America was known for protecting the entire planet during its tenure.
The Justice League International was designed to have a less focus in the United States, to incorporate heroes from around the world and allow DC to dust off some of its older properties. The JLI was also more of a humor-oriented book given its core membership including Booster Gold and Ted Kord as the Blue Beetle. These two characters were comedy gold in the hands of the JLI writers and the book enjoyed a brief moment in the sun before being replaced. After Giffen and DeMatteis' departure. DC created numerous spin-off titles. In 1996, the series was canceled, along with spinoffs Justice League Europe, Extreme Justice, and Justice League Task Force.
All of these variations on the Justice League were attempting to bring the JLA back to prominence but with limited success.
Volume Two of the Justice League of America ran for 60 issues and would be recreated in the New 52 Universe as purely the Justice League. Returning to the classic Super Seven lineup of Batman, Superman, Flash, Wonder Woman, Green Lantern (Hal Jordan), Aquaman and former Teen Titan, Cyborg (likely to add some diversity to the ranks). This Justice League was unfamiliar with each other, basically restarting the seminal team from scratch.
With the 2011 relaunch of its titles, DC Comics released a second volume of Justice League. In July 2016, the DC Rebirth initiative relaunched the Justice League comic book titles with the third volume of Justice League. Since its inception, the team has been featured in various television programs and video games and is set to appear in the 2017 film of the same name.