Lei is a garland or wreath. More loosely defined, a lei is any series of objects strung together with the intent to be worn.The most popular concept of a lei in Hawaiian culture is a wreath of flowers presented upon arriving or leaving as a symbol of affection.This concept was popularized through tourism between the Hawaiian Islands and the continental United States in the 19th and 20th centuries.he most popular concept of a lei in Hawaiian culture is a wreath of flowers presented upon arriving or leaving as a symbol of affection. This concept was popularized through tourism between the Hawaiian Islands and the continental United States in the 19th and 20th centuries.