Differences between Severity ,Priority and Status

In market there are many bug tracking and project management tools available. These tools allow us to keep essential information of a bug or task. You will see there are three places have to fill when key in a task. Those three places are Status, Priority and Status of a bug/task. Let's see what those stand for. 

	Severity	Priority	Status
Connotation	Severity of a bug means how much it affecting to functionality of the software. Total damage it can do.	Priority means how fast a bug or task should be resolve.	Status means the current position of the bug/task.
Types	Critical           Major           Moderate           Minor           Cosmetic	Low          Medium          High	New          Active/Open          Resolved/Fixed          QA In progress          Reopen          Closed/Completed

What is the different between major bugs and critical bugs?

Critical	Major
Tester cannot go further with testing. System terminates/ crashes with this bug and no alternative methods to perform the test. This is an end point of test.	Tester cannot go further with testing. System terminates/ crashes with this bug but there are alternative methods to perform the test.