Priority : Priority will assign the developevers, depends 
on the cusomer requirement they will assign the priority

Seviority : Seviority means  the defect how seriously 
effecting the functionality .. it will be assigned Test 
Engineer 

Serviority is classified critical, high, low, cosomotic

Priority means Which defect should rectify first.

Severity means Seriousness of the defect.

Severity is the impact of the bug on the application.  
Severity may be classified as critical, major and minor.  
Severity status is given by the tester.

Priority is how fast the defect has to be fixed.  It may be 
classified as low priority, moderate priority and high 
priority.  Priority status is given by the team lead.

priorty : how soon it has to be fix.
         
         * High
         * low
         * Medium

severiorty : how had the bugs.
          
         * critical
         * Major
         * Minior

priorty 3 Type
         
         1 High
         2 low
         3 Medium

severiorty          
         
         1 critical
         2 Cosmatic
         3 Deficient