Perpetual Licenses: These licenses never expire. However, they do require an annual Maintenance agreement in order to receive new versions and updates. A 1 year Maintenance agreement is included with a new Perpetual License.
Annual Licenses: These licenses will allow a system to operate for one year. At that point in time, a new Annual License will be required for the system to continue operating. This license includes new versions and all updates (no additional annual Maintenance is required)
Maintenance: This only applies to Perpetual LIcenses. An Annual Maintenance agreement is required for a Perpetual LIcense to receive new versions and service pack updates.