All machines that may run the software must have network access. If all the licenses are in use, the program stops and returns the information to the user. Software agreement licenses are located in the box when you purchase software at your local computer store. When you acquire through the proper procedures, the SVLA allows you legal use of specific software. Recurring annual fees, which may or may not be mandatory for continued use of the software.
Maintenance usually includes technical support and updates.
For programs that are not paid-up at initial purchase, maintenance is the annual fee to keep the program running. A license where only so many specific machines may have the software installed. Usually requires registration of CPU serial numbers. It does not imply a right to updates, which are typically sold seperately as part of a maintenance agreement, or on a per-update basis. If these cases, if the fee is not paid, the software quits working.