The Social Network is a film about the setup and first 6 to 12 months of Facebook.
It starts out showing Mark Zuckerberg with his ex girlfriend who just happens to split up with him. In a rage he first blogged about her while hacking sororities photos so he could set up a website, Facesmash to make himself feel better. This rated girls against each other to see who was 'hotter'.
Seeing the success of this Zuckerberg was perused by Cameron and Tyler Winklevoss who wanted to set up a dating website for Harvard students knows as the Harvard connection. After the first meeting or two Zuckerberg took somewhat of the same idea and used different processes to set up 'the facebook' a complete social network site for only people with a harvard email address.
Soon afterward, Mark approaches Eduardo and tells him of his idea for what he calls "Thefacebook", an online social networking website exclusive to Harvard University students. He explains this would let people share personal and social information securely. Eduardo agrees to help Mark, providing $1,000 to help start the site. They distribute the link to Eduardo's connections at the
Phoenix S-K final club, and it quickly becomes popular throughout the student body. When they learn of Thefacebook, the Winklevoss twins and Narendra believe Zuckerberg had stolen their idea while stalling on their website. Tyler and Divya want to sue Mark for intellectual property theft, but Cameron convinces them they can settle the matter as "Harvard gentlemen" without the courts. Meanwhile, Mark continues to add features like "relationship status" to the profile page, since "people don't walk around wearing signs."
At a visiting lecture by Bill Gates, fellow Harvard University student Christy Lee introduces herself and her friend Alice Cantwel to Eduardo and Mark. She asks the boys "Facebook us"; their use of this phrase impresses both of them. Christy invites them to a bar where Mark runs into Erica, who is not aware of Thefacebook because she is not a Harvard student. Mark decides to expand the site to more schools. As Thefacebook grows in popularity, they expand to other schools in the Northeastern United States, while the Winklevoss twins and Narendra become angrier at seeing "their idea" advance without them. Cameron refuses to sue them, instead accusing Mark of violating the Harvard student Code of Conduct. Through their father's connections they arrange a meeting with Harvard President Larry Summers, who is dismissive and sees no potential value in either a disciplinary action or in Thefacebook website itself.
Through Christy, now Eduardo's girlfriend, Eduardo and Mark arrange a meeting with Napster co-founder Sean Parker. When Christy, Mark, and Eduardo meet Sean, Eduardo becomes skeptical noting Sean's problematic personal and professional history. Christy thinks Eduardo is jealous of Sean, and attempts to calm him to avoid a scene. Sean presents a vision for Facebook similar to Mark's and impresses him. In a parting comment, Sean suggests they drop the "The" from Thefacebook.
At Sean's suggestion, Mark moves the company to Palo Alto, while Eduardo remains in New York seeking advertising support. Meanwhile in England, while competing in the Henley Royal Regatta for Harvard, the Winklevoss twins discover Facebook has expanded to a number of universities there. Cameron finally relents and they decide to sue. When Eduardo visits from New York, he is angered to find Sean is living at the house they have rented and is making business decisions for Facebook. After arguing with Mark, Eduardo freezes the company's bank account and returns to New York. Upon returning, Christy argues with Eduardo about his Facebook profile, which still lists him as "single". When Christy questions Eduardo about why he has not changed his Facebook profile, he tells her he does not know how to, further infuriating Christy because she believes he is lying. She cites his profile as evidence he cheated on her with promiscuous women in Silicon Valley and sets fire to a scarf he has given to her. While Eduardo extinguishes the fire, Mark reveals on the phone that they have secured money from an angel investor through Parker's contacts. Eduardo ends his relationship with Christy.
Eduardo soon discovers the deal he signed with Sean's investors has allowed them to dilute his share of the company from thirty-four percent to three hundredths of a percent, while maintaining the ownership percentage of all other parties. He confronts Mark and announces his intention to sue him. Later that night, during a party celebrating Facebook's 1 millionth member, Sean and a number of Facebook interns are arrested for possession of cocaine.
The framing device throughout the film shows Mark testifying in depositions in two lawsuits: one filed by the Winklevoss twins, and the other filed by Eduardo. In the final scene, a junior lawyer for the defense informs Mark they should settle with Eduardo, since the sordid details of Facebook's founding and Mark's personality will make a jury highly unsympathetic. The film ends with Mark sending a friend request to Erica on Facebook, and refreshing the page every few seconds waiting for a response.