Old World Sparrows are a group of small passerine birds forming the family Passeridae. They are also known as True Sparrows, a name also used for a particular genus of the family, Passer. They are distinct from both the New World sparrows, in the family Passerellidae, and from a few other birds sharing their name, such as the Java sparrow of the family Estrildidae. Many species nest on buildings and the house and Eurasian tree sparrows, in particular, inhabit cities in large numbers, so sparrows are among the most familiar of all wild birds. They are primarily seed-eaters, though they also consume small insects. Some species scavenge for food around cities and, similarly to gulls or rock doves, will happily eat small quantities of virtually anything.

New World sparrows are a group of mainly New World passerine birds, forming the family Passerellidae. They are seed-eating birds with conical bills, brown or gray in color, and many species have distinctive head patterns. Although they share the name sparrow, New World sparrows are more closely related to Old World buntings than they are to the Old World sparrows (family Passeridae). New World sparrows are also similar in both appearance and habit to finches, with which they sometimes used to be classified.

Sparrow is a species of small Passerine birds, also acknowledged as True sparrows or Old world Sparrows. It originates from North Africa and is also found in Asia, Australia, Europe, New Zealand and North America. Sparrows cannot be found in forests or deserts, unlike other birds. It prefers being in close association to human settlement, including urban and rural areas. They inhabit on ideal sparrow habitat nesting on buildings, roofs, and houses.