From Wikipedia:
Modern Family is an American mockumentary comedy TV series. The half-hour series, which was created by Christopher Lloyd and Steven Levitan, is produced by Fox Television Studios. The mockumentary follows the families of Jay Pritchett (Ed O'Neill) his daughter Claire Dunphy (Julie Bowen), and his son Mitchell Pritchett (Jesse Tyler Ferguson) who live in Los Angeles. Claire is a homemaker mom in a traditional family, married to Phil Dunphy (Ty Burrell); they have three children. Jay is married to a much younger woman, Gloria (Sofía Vergara), and is raising a pre-teen stepson. Mitchell and Cameron (Eric Stonestreet) are a gay couple who have adopted a Vietnamese baby, Lily. The show premiered on ABC on September 23, 2009 to critical acclaim.
The show revolves around three families that are interrelated through Jay Pritchett, Mitchell Pritchett and his daughter Claire Dunphy. The families meet for family functions, around the neighborhood, and cross-family bonding.