Short answers, pulled from the story.
Spider-Man first appeared in the comic book Amazing Fantasy #15, which hit newsstands in August 1962. This issue marked the debut of the character created by writer-editor Stan Lee and artist Steve Ditko.
Writer-editor Stan Lee and artist Steve Ditko created Spider-Man through a collaborative process involving creative disputes over his conception and design. Lee initially approached Jack Kirby for the concept but ultimately turned to Ditko who redesigned the character completely with the radioactive spider bite origin and iconic costume.
Major storylines that changed the series include the death of Gwen Stacy in June 1973 during The Night Gwen Stacy Died arc and the introduction of the black symbiote costume in Secret Wars during the 1980s. Other significant shifts occurred when Peter Parker married Mary Jane Watson in 1987 and when Doctor Octopus took over Peter's body as the Superior Spider-Man for 31 issues starting in 2014.
Global retail sales of licensed Spider-Man products reached approximately $1.3 billion in 2014, making him the world's most profitable superhero that year. This figure exceeded the combined licensing revenue of Batman, Superman, and the Avengers.
Spider-Man is considered groundbreaking because he was the first teenage hero who could age with the series and operated independently unlike previous teen sidekicks. Writers used the character to explore generational gaps, social anxiety, and moral weight while allowing readers to identify with his self-doubt and loneliness.