How is the House of Lords primarily divided according to membership type?

The primary division of the House of Lords is based on three distinct categories of membership types: life peers, bishops, and hereditary peers. Life peers are appointed for their lifetime and hold the majority of seats in the House. They bring expertise from various fields such as law, business, and public service. Bishops represent the established Church of England, with a specified number of bishops (the Lords Spiritual) having seats in the House. Finally, hereditary peers originally inherited their titles, but since the House of Lords Act 1999, only a limited number can remain as life peers, with the rest having been removed from daily membership.

The correct response emphasizes the actual and formal structure of the House of Lords, which includes these categories of members. Each category contributes to the functioning of the House, ensuring a diverse representation that is not solely based on electoral politics, thus differentiating it from the political dynamics in the House of Commons.