In Instanta Facility, a work request describes a unit of work submitted to the operation team by an end-user or an officer. Different organizations use Instanta facility to track different kinds of requests, which can be anything from maintenance requests, procurement requests, float requests, item requests etc.
Your end-user submits a request through the end-user web portal or mobile app while an application user or officer submits a work request by login into the Instanta web interface. The submitted request becomes a work order after it has been approved.
Therefore a work order is an approved work request or a unit of work that has been authorized for execution.