Difference between priority and severity?

"Priority" is associated with scheduling, and "severity" is associated with standards. "Piority" means something is afforded or deserves prior attention; a precedence established by order of importance (or urgency). "Severity" is the state or quality of being severe; severe implies adherence to rigorous standards or high principles and often suggests harshness; severe is marked by or requires strict adherence to rigorous standards or high principles, e.g. a severe code of behavīor. The words priority and severity do come up in bug tracking. A variety of commercial, problem-tracking/management software tools are available. These tools, with the detailed input of software test engineers, give the team complete information so developers can understand the bug, get an idea of its 'severity', reproduce it and fix it. The fixes are based on project 'priorities' and 'severity' of bugs. The 'severity' of a problem is defined in accordance to the customer's risk assessment and recorded in their selected tracking tool. A buggy software can 'severely' affect schedules, which, in turn can lead to a reassessment and renegotiation of 'priorities'