Open In the Open status you can enter and post Journals.

Closed In this status Journal entry and posting not allowed until accounting period is reopened. Reporting and inquiry allowed.

Permanently Closed In this status Journal entry and posting not allowed. You cannot change this period status. Reporting and inquiry allowed. You can change the status.

Never Opened Journal entry and posting are not allowed. General Ledger assigns this status to any period preceding the first period ever opened in your
calendar, or to any period that has been defined, but is not yet future-enterable. You cannot change this period status.

Future-Entry Journal entry is allowed, but posting is not. Your period is not yet open, but falls within the range of future-enterable periods you designated in the Set of Books window. You cannot change this period status without using the concurrent process to open the period.