Halflings are nomadic, family-centered wanderers found throughout the known world. They are generally good natured, though mercurial. They are quick to laugh, to anger, and to forgive. Though they once possessed a homeland and language, both were lost during the Ubrekti Empire. Since that time, the halflings have lived as wanderers and over-land and river-boat tradesmen with no political organization, existing instead in matriarchal bands made up of several dozen families. Otherwise, halflings do not interact with a larger racial community, except in passing or during irregularly called hearthwarmings.
Halflings are not "integrated" into human society in the traditional sense, but are allowed to exist there with relative autonomy under the Concord of the Highways. Both sides, more or less, have lived up to the Concord, and there is minimal animosity between the groups in the modern day.
Halflings tend to organize and travel is small to medium size bands of several to several dozen families. In general, however, such bands can be classified as one of two types: Boat Tribes or Road Tribes.
Boat Tribes tend to be smaller in size, and make their living as fishers, boatmen, and ferrymen on the rivers and sometimes even on the coast. They are comparatively settled: seasonally migrating ferrys or running regular delivery routes up and down the mainland's interior waterways.
Road Tribes, on the other hand, can be anywhere in size from large to sprawling. In many ways, a larger band of road halflings might operate as a small village on mule back. They are allowed to maintain herds of grazing livestock under the Concord of the Highways, and often set up exotic goods bazaars outside major cities. Some bands simply go the direction the wind takes them, while others travel a regular trade route, albeit one that might take several years or more to circuit.
Another organization structure for halflings are the "Hand" Tribes. This grouping, like all Halfling social distinctions, is not very well-defined, but often is seen to represent the more disreputable end of the Halfling extended family. Hand halflings can be found both among Road Tribe or Boat Tribe halflings, and the Hand themselves are further subdivided into color-distinguished bands. For example, the Blue Hand are known as thriving grey marketeers who often settle in conflict zones and assume control of abandoned infrastructure, while the Green Hand abandon both road and boat and retreat into isolated wilderness settlements. The other Hand tribes are the Red Hand, White Hand, and Indigo Hand.
Additionally, among the Hand themselves is rumored to be the Black Hand, a tribe of poisoners, infiltrators, and assassins who act as intelligence network-slash-vigilante assassin guild that lives embedded among the five Hand tribes.
According to their own lore, the Hand are the descendants of the halfling nobility of old, but most non-Hand halflings greet such claims with extreme skepticism.
There also exist Ghost halflings. Less than a coherent subgroup and more a motley collection of outcasts and weirdos (which, for halflings, is a high bar), they're known for liking cats more than dogs and generally otherwise being completely incomprehensible.
At creation, halflings should be either part of a Boat Tribe or a Road Tribe, or otherwise a member of one of the Hand tribes. In 5e, halflings may choose alternate racial traits to reflect these cultural differences.