Jack Dorsey is an American entrepreneur best known as the co-founder of Twitter, a popular social media platform that revolutionized how people communicate online. He also founded Square, a financial services and mobile payment company, which has significantly impacted the way small businesses handle transactions. Dorsey was born on November 19, 1976, in St. Louis, Missouri. He has been a prominent figure in the tech industry, known for his innovative ideas and leadership style. His work has earned him recognition as one of the most influential people in technology today.