Blocker:This also called as Show stopper.
for eg. login of an application is failed then tester
cannot test the application further.So this stops the 
application testing.

Login failure
Navigation Failure
Registration failure of some application



Byee

rajendra 
rajendra_penumalli@yahoo.com
9885162742

Mr.Rajendra,pliz explain in details with all types of bugs 
with examples.thanks.....

low level bug is also called as cosmetic bug. i.e if there
is change in the spelling or colour mistake then we call it
as low level bug. it will be having low seviority(s1). and
priority is p5(i.e before delivery we can fix the error)

Medium level bug : if there is any mismatch with the
expected and actual values then we call it as medium level
bug, here the seviority is s2. and priority is p4(i.e with
in a week)

High level bug: It is an unexpected error or output, and the
seviority is s3. and priority is p3(i.e with in 2-3 days)


very High or Major level bug: any fatal error or  the module
crashes while running the application we call it as high
level bug. Seviority is s4 and priority is p3(i.e with in a 
day)Also if there is important busniess rule violation or 
there is a logical error.

Urgent or Critical bug: application crash, seviority is s5
and priority is p1(i.e it has to be fixed with in 2 to 3 
hours )

Minor Bug :Like simple GUI defects,wrong spellings etc.

Blocker,critical,Mojor,Mormal,Minor,Tivial,Enhancement Bug

Lets see the example of these 

1) blocker >> application crashes during installation 
2) critical >> while performing main functionality of 
product ( main purpose to use that product ) application 
crashes .
3) Mojor >>  after filling the form of any application , 
form fail to submit after clicking on submit button ( 
records are 

not found in database )
4) minor >> spelling mistakes
5) tivial >>  after performing particular steps application 
produces the msg which is not user friendly like vc++ error 
code