According to ITIL 4, an incident is an unplanned interruption to a service or reduction in the quality of a service. An incident can be classified as such based on whether or not the service level agreement (SLA) was breached. However, ITIL allows for raising an incident even before an SLA or targets have been breached in order to limit or prevent impact. A problem, on the other hand, is a cause or potential cause of one or more incidents. Problems can be raised in response to a single significant incident or multiple similar incidents, or they can be raised without the existence of a corresponding incident.

ITIL encourages organizations to distinguish between incidents and problems because they are often treated and resolved differently. Incident management focuses solely on handling and escalating incidents as they occur to restore defined service levels. The main goal of incident management is to take user incidents from a reported stage to a closed stage. Incident management does not deal with root cause analysis or problem resolution. Problem management, on the other hand, is focused on preventing incidents or reducing their impact.

ITIL offers guidance around incident management to minimize the potential negative impacts and ensure smooth business operations. Common ITIL incident management activities include detecting incident details, matching incidents against known problems, resolving incidents quickly, and prioritizing incidents in terms of impact and urgency. Incident management is a separate practice from problem management in ITIL 4 because they often require different skill sets and activities.