Viscount

A Viscount rules a Viscounty, which is a fiefdom, though to become a Viscount, the family traditionally has to have lands inside the Viscounty, meaning a Viscount typically also holds a title as Baronet of some particular tract of land within the viscounty. The seat of the Baronetcy then functions as a Country Estate for the Viscount, being the lowest rank of titular nobility and as such, requires the Viscount to maintain three estates - their Palace (where they hold Court), their Country Estate (their personal home) and the Town House (their home in the settlement in which their Liege holds court).
Some regard most Barons to rank below a Viscount in rank and status, but this is only because most Baronies are small - in theory, a Barony could be large enough (and they often are) that they can be subdivided into multiple Viscounites, making Viscounts, potentially, subservient to a Baron - though at such a point in time, the Baron would most likely be recognized as an Earl in most cases. A Viscount is, commonly, a hereditary title, though it doesn't necessarily pass from father to son, but it does typically stay within the same family.
The Country Estate of a Viscount is often looked after by another member of the family who acts as the Steward of those lands, but is effectively the Baronet. Similarly the Viscount commonly appoints a Courtier from the family to live in the Town House and act as their eyes, ears and voice in the court of their liege.

Type

Nobility, Hereditary