Equivalence partition:
Eg: suppose i have 200 bugs and i have test them with in 
given period of time.In this situation i can only do is to 
categorise the bugs as per to their severity, priority, etc 
and this division is called as equivalence partition

Boundary Value Analysis:
Eg: Take a login page where the condition for Username is 
to enter the values within the limit of 5-15 characters.
so, the tester can test this, as
5,5+1,5-1,6 to14,15,15+1,15-1

Hai Swapna ur misunderstood the Equivalence partition
technique.
This is used to create test cases,Test data.
Not for resting bugs reported and fixed in previous 
build.
ok
rajendra
rajendra_penumalli@yahoo.com

Yes Rajendra is Correct,

ECP is nothing but divide test cases into small but till 
equily effective groups. 

This tech. will use to reduce the no. of test cases.

If I m wrong please correct me.

Shyam

Shyam 
Using ECP we can split test cases into positve and negative
test cases.this not to reduce the  number of testcases
but to give more clarity test cases development.
ok
rajendra
rajendra_penumalli@yahoo.com

hi shyam what u entered is correct but u didn't explain 
about the BVA....that is it is checking the valid output by 
entering the extream values of the boundaries...i mean just 
enter the upper and lower values of boundaries...

Hi shyam 

Take username field as example that have req for entering 5
to 15 charecters

BVA for this is 

min = 5
min+1 = 6  pass
min -1= 4  fail
max   = 15 pass
max+1 = 16 fail
max-1 = 14 pass

and moving to ECP: Equavelance 
partition

Take same username field which accepts a-z and 0-9 charecters

Valid
a-z 
0-9

invalid

A-Z
Special charecters.... etc 

Hope this will be correct 
please correct me if i miss some thing