The itil role enables the user to perform actions related to incident, problem, change, and configuration management. This role is part of the ITIL framework, which is a set of best practices for delivering IT services. According to the ServiceNow documentation1, the itil role can do the following:
* Create and update incidents, problems, and change requests
* View configuration items (CIs) and their relationships
* Add comments and work notes to tasks
* Approve or reject change requests
* Close resolved incidents and problems
* Reopen closed incidents and problems
The other roles listed in the question have different functions and permissions. For example, the procurement_user role can request and track hardware purchases2, the inventory_admin role can manage stockrooms and transfer orders3, the discovery_admin role can configure and run Discovery to populate the CMDB4, and the asset role can view and edit asset records5.
References: 1: Incident Management - Product Documentation: San Diego - ServiceNow 2: Procurement - Product Documentation: San Diego - ServiceNow 3: Inventory Management - Product Documentation: San Diego - ServiceNow 4: Discovery - Product Documentation: San Diego - ServiceNow 5: Asset Management - Product Documentation: San Diego - ServiceNow