To the front-line technician, the two most important ITIL processes are Incident and Service Request Management. These are the bread and butter of front-line work, and most tickets handled by a support desk will fall into one of these categories.
A ticket is an incident when something has gone wrong. A file may have been deleted, a system may have stopped working or simply have become slow. ITIL defines an incident as:
An unplanned interruption to an IT Service or a reduction in the Quality of an IT Service. Failure of a Configuration Item that has not yet impacted Service is also an Incident.
Service requests are tickets where a user asks for information, access or a predefined change. A user may want advice on what system to choose, request additional permissions on the network, or want a configuration changed. ITIL defines a service request as:
A request from a User for information, or advice, or for a Standard Change or for Access to an IT Service.
When processing tickets, it is important to not only read what the user writes, but also understand the underlying need. Something reported as an error by the user may in fact be a perfectly standard configuration change, such as claiming that the default template in Word is faulty. Though the user experiences the reported need as something being wrong, this is in fact a simple service request.