The comic book's originally published by Marvel and on sale long ago in shops far far away, offered the world the first glimpse of what was to become a global phenomenon. The comics were actually on sale before the film was completed which would explain why readers were confused that the Jabba the Hut scene in the comic was not originally in the finished film - least not until Lucus started tinkering with his digital toolbox decades later.
In fact the comics had actually finished the first movie storyline and were onto all original stories by the time the movie hit cinemas.
Now the original comics are available to buy again in graphic novel format from those nice people at Dark Horse. The first volume collects the first 26 issues of the original Star Wars Comic and is available now.