The host is the main operator of a battle, which consists of a BotBr.

Hosts operate either a Minor Battle (usually an OHC) or a Major Battle (e.g. Winter Chip)

After either type of compo is closed for entries it is up to the host to either close voting themselves when everyone who participated is done or let the BotB system close voting after a day.

For Major Compos, a BotBr has to set the specific date for when the compo ends.

If you want to host an OHC, you must have participated in at least ten OHCS of a specific type and you have to provide a 750 boon deposit. Parasites cannot host OHCs.