Suppliers are generally outside providers of purchase items and other services.
Resources refer to internal human resources (e.g. a member of staff responsible for cleaning would be a resource).
Suppliers/resources are assigned to tasks on maintenance/project schedules.
An outside supplier may be required to complete the task in which case a purchase order should be raised.
If an internal resource is available to fulfil the task, a purchase order would not be required.
iTech Facilities Management does not make any specific distinction between Suppliers and Resources.