In what way is the film like the sources?

George Lucas's iconic Star Wars trilogy is, perhaps the most famous and memorable film franchise in history. Of course, like most art, Star Wars borrows from very many artistic works and much culture that had existed before its inception.
Star Wars is, in a way, a collection of the innumerable amount of things that influenced George Lucas as a child and as a film student. Most notably, at least stylistically, would be the television serial Flash Gordon as well as the filmography of the Japanese filmmaker Akira Kurosawa.
In Flash Gordon, a psychotic and megalomaniacal space villain has his fortress invaded by two heroes in disguise. In the original Star Wars, Luke Skywalker, Han Solo, and team invade Darth Vader's Death Star by dressing up as the iconic Storm Troopers. Flash Gordon also features laser guns and spaceship dogfighting, two characteristics that feature heavily in all three original Star Wars films. Lastly, the memorable opening crawl that opens each Star Wars film and serves as a narrative exposition to introduce the audience to the strange, sci-fi world of Star Wars was lifted from a similar crawl that opened Flash Gordon Conquers the Universe.
In terms of Kurosawa's filmography, Lucas himself frequently admitted the late Japanese director to have been a significant influence on his work and would actually go on to help produce Kurosawa's jidaigeki epic Kagemusha when Japanese producers would refuse to cough up money. While Lucas took many stylistic and thematic influences from Kurosawa—particularly that of the Samurai's code of mercy, honor, and morality, which heavily makes up the way of the Jedi—the most notable comparison comes from Kurosawa's 1958 masterpiece The Hidden Fortress. In The Hidden Fortress, the audience follows the point of view of two lowly peasants who become entangled in a political plot to escort a princess across dangerous turf. Replace the two peasants with the lovable droids R2-D2 and C-3PO and the similarities are uncanny!
Apart from art and media influences, Star Wars is also quite heavily influenced by Eastern religion. The Chinese concept of Qi, which basically is the idea of a single massive life-form making up all living beings, is an inspiration for the Force. The iconic line "May the Force be with you . . . and also with you" mirrors the Catholic phrase "May the Lord be with you . . . and also with you." Lucas himself has suggested the Force to essentially be a conglomeration of all the world's major religions, a sort of disproven way of life that skeptics—such as Han Solo—consider to be hokey nonsense.
Essentially, Star Wars takes countless influences, digests them, and creates something culturally massive. Star Wars, in most ways, becomes more significantly memorable than its influences, for it transcends the entire idea of cinema and becomes a cross-cultural, multimedia phenomenon that exists in toys, novels, comics, and television.