Holds are the basic unit of life on Pern. They consist of small settlements, the largest being perhaps 10,000 people, with the core being a cave complex, which serves as a central storage facility for crops and other resources, and the center of social life. Surrounding the Hold Proper are various stone buildings. The Major Holds are governed by Lords Holder and Ladies Holder, and minor Holds "look to" the Major Holds, that is, they pay tribute, and in exchange, receive assistance as needed.
Minor Holds are governed by Holders.
When a Lord Holder or Lady Holder in her own right (as opposed to the wife of a Lord Holder) dies, a Conclave of Lords Holder is called to choose an heir, or, more commonly, confirm the previous Lord's choice. The Conclave may reject the Lord's choice, but this is rare, and in actual effect, the Conclave is generally a formality.
It should be noted that the Conclave has no real power of enforcement, other than persuasion. Fax, for example, was never Confirmed in any of his holds, yet this had no effect on his power.