the execution of build under customer expected load and
customer expected configuration is called load testing


execution of our build under customer expected configuration
and various load levels from low to peak to test whether the
build is working or not is called load testing

load testing: check login performance under customer
expected load
stress testing:check login reliability under various load levels

Load Testing:  Increase n number of users and check the  
               response time of the applications.

Stress Testing : Increase the n number of transactions and 

                 check the response time of the applications

load testing:
        upto the limit how the system is working.for 
example, the load limit is 1000 for that application then 
we have to test upto load 1001.

stress testing:
        beyond the limit how the system is working. For 
example, the load limit is 1000 for that application then 
we have to test upto load 999.

load testing--Testing the application behaviour under 
cetain load

for eg1: if an application is being loaded with 10 users
(load)
        then application performance will be very fast for 
the 10 users
        (i.e Request/Respone)

for eg2: If an application is being loaded with 100 users
(load),then Request/Respone
         will gradually decrease


Stress Tesing : Testing the application behaviour beyond 
the limit
                it meanse at what particulat point of time 
system break to perform