Egrets /ˈiːɡrət/ are herons that have white or buff plumage, developing fine plumes (usually milky white) during the breeding season. Egrets are not a biologically distinct group from herons and have the same build.
Many egrets are members of the genera Egretta or Ardea, which also contain other species named as herons rather than egrets. The distinction between a heron and an egret is rather vague, and depends more on appearance than biology. The word "egret" comes from the French word aigrette that means both "silver heron" and "brush", referring to the long, filamentous feathers that seem to cascade down an egret's back during the breeding season (also called "egrets").
Several of the egrets have been reclassified from one genus to another in recent years; the great egret, for example, has been classified as a member of either Casmerodius, Egretta, or Ardea.
Several Egretta species, including the eastern reef egret, the reddish egret, and the western reef egret, have two distinct colours, one of which is entirely white. The little blue heron has all-white juvenile plumage.