ITSM Overview and ITSM Fundamentals
What ITSM is for
IT Service Management is the set of practices that make IT services predictable: work is captured, classified, prioritised, assigned, and measured. ITIL 4 frames this as a service value chain supported by practices rather than the older ITIL v3 'processes' - a distinction that shows up in terminology questions. ServiceNow's ITSM suite maps products onto those practices: Incident, Problem, Change, Knowledge, Service Catalog/Request Fulfillment, CMDB, and Service Level Management.
The task family
Almost every ITSM record extends the task table. Incidents, problems, change requests, requests, requested items, and catalog tasks all inherit shared fields (number, state, assignment group, assigned to, priority, parent), shared behaviours (approvals, SLA timers, activity stream, work notes), and shared reporting. When a question asks where to configure something that affects several modules at once, the answer is usually the shared task-level mechanism rather than a single module.
Classifying work correctly
Four questions separate the modules: something broke (incident), the cause is unknown and recurring (problem), something must be modified deliberately (change), or someone wants something they do not yet have (catalog request). This classification is the most heavily tested skill in the whole exam.
Traps
Assuming an inbound phone call is automatically a request - in ServiceNow only catalog submissions create requested items. Treating priority as freely chosen when it is derived from impact multiplied by urgency. Assuming CMDB and SLM are optional extras, when incident CI fields and task SLAs depend on them. Confusing the name of a practice with the name of a table.
Rule of thumb
Ask whether the user wants something restored or something delivered. Broken or degraded in production means incident; a want, an access grant, or a new item means request; a known recurring cause means problem; a planned modification means change.