Defect priority indicates based on how badly a defect it affects the business.
High Severity and High Priority
Consider an online game where users are unable to login into their accounts. This problem makes the game unplayable and can cause huge revenue losses as well. These defects drastically affect both functionality and business. They are, therefore, high in both severity and priority and need to be resolved quickly.
Low Severity and High Priority
Let's continue with the same online gaming example. Users can access their account and play the game but the in-app store to buy premium avatars is inaccessible. This defect is of low severity since the avatar doesn't affect the gaming experience negatively, but it is of high priority because it adversely affects revenue.
High Severity and Low Priority
Assume that users with significantly older versions cannot log in to the gaming software. If the company knows that users running older versions of their software rarely make in-app purchases, this defect can be assigned a low priority. However, since users are unable to play the game, it will be classified with high severity.
Low Severity and Low Priority
These are cosmetic issues that affect neither the business nor the end-users.