"Karmanyevadhikaraste ma phaleshu kadachana, Ma karma phala hetur bhurmatey sangostva akarmani."

Definitions

2 tier and 3 tier apps:

http://www.softwaretestingclass.com/what-is-difference-between-two-tier-and-three-tier-architecture/


Deffered:  status means fix it as a geniune defect but
decided to rectify in next version.All the deferred defects
will be kept in product enhancement document

the bug is expected to be fixed in next releases. The reasons for 
changing the bug to this state have many factors. Some of 
them are priority of the bug may be low, lack of time for 
the release or the bug may not have major effect on the 
software.