and see text Passerida is, under the Sibley-Ahlquist taxonomy, one of two parvorders contained within the suborder Passeri (standard taxonomic practice would place them at the rank of infraorder).

While more recent research suggests that its sister parvorder, Corvida, is not a monophyletic grouping, the Passerida as a distinct clade are widely accepted.

Usually skulking in shrubby vegetation, many are extremely drab (most of birdwatchers' "little brown jobs" belong here) and rely on complex and often melodious vocalizations as social signals; others are less accomplished singers but produce a diversity of squeaking and twittering calls.

The sexes usually look alike, though in some the males are noticeably brighter, typically with vivid yellow, green and blackish hues.

Some brightly colored (often with dark bluish hues and/or iridescence) and in such cases usually strongly sexually dimorphic; more often, however, sexes rather alike, with drab brownish plumage spotted and streaked (particularly on the underside) for camouflage.

Many have highly accomplished, complex, melodious and loud songs; a considerable number is capable of sophisticated vocal mimicry.