Impact, urgency, priority

Answer:
Impact, urgency and priority are usually used by incident/problem/change management.
Impact describes the effect an e.g. incident has on the service i.e. business process.
Urgency describes how long it takes that an e.g. incident has significant impact on the service i.e. business process.
Priority describes how important an incident (change or a problem) is. Priority is based on impact and urgency..
These articles can help you:
" Three key elements of assessment and evaluation of changes according to ITIL". https://advisera.com/20000academy/blog/2015/06/30/three-key-elements-of-assessment-and-evaluation-of-changes-according-to-itil/
"All about Incident Classification" https://advisera.com/20000academy/knowledgebase/incident-classification/"
and this webinar:
"ITIL Incident Management Process Demystified" https://advisera.com/20000academy/webinar/itil-incident-management-process-demystified-free-webinar-on-demand/