Here is a comprehensive summary of the Wikipedia article about The Fantastic Four:
The Fantastic Four, Marvel Comics' pioneering superhero team, first appeared in The Fantastic Four #1 in November 1961, co-created by artist Jack Kirby and editor Stan Lee. This debut marked a new era of realism in comics and established the influential "Marvel method" of production. The team consists of four individuals who gained superpowers from cosmic rays during a scientific mission: the brilliant, stretchy leader Mister Fantastic (Reed Richards); his wife, the invisible and force-field-generating Invisible Woman (Susan Storm); her fiery brother, the Human Torch (Johnny Storm); and their super-strong, stone-skinned friend, the Thing (Ben Grimm).
Breaking traditional superhero archetypes, the Fantastic Four are portrayed as a relatable, albeit dysfunctional, family who openly embrace their celebrity status rather than maintaining secret identities. They are renowned for their complex relationships and frequent encounters with iconic villains like Doctor Doom, the planet-devouring Galactus, and the Silver Surfer. The team's enduring popularity has led to numerous adaptations across various media, including video games, animated series, and live-action films.