Explain the difference between bug severity and bug priority?

Severity : Bug Severity defines how much impact a bug can cause to the application. Tester defines the severity. We can set the severity to High, Moderate, Low based on how severe the bug is?

Priority : Bug Priority defines how early the bug can be fixed? If the bug causes the major failure and is in the most used part of the application, the lead/ developer prioritizes it to the high priority.

Examples:

• High Severity & High Priority: A bug that causes ‘Login’ page fail is set to High Severity because it is critical function that cause the entire purpose get affected. Priority is high too because it should be fixed as early as possible since it is the primary function.
• High Severity & Low Priority: If a bug is potential enough to cause huge loss, but, it is in the less visited page, the severity is high but priority can be ‘moderate to low’. It should be fixed but they can delay the fix as it has less possibility to be occurred.
• Low Severity & High Priority: Cosmetic error in Organization’s name doesn’t affect the basic functionality. But, it is loss to the Organization’s image. So, it should be prioritized to be high to get fixed as early as possible.
• Low Severity & Low Priority: Typos in any other content. They can be corrected after all the potential bugs are corrected.