Endurance Testing: Checks for memory leaks or other 
problems that may occur with prolonged execution. 

it is also called soak testing. it is testing the 
application under heavy volumes of data for a prolonged 
period of time

Endurance testing is nothing but Security Testing
Testing how well system provides security against 
unauthorized internal or external access

Endurance Testing: Checks for memory leaks or other 
problems that may occur with prolonged execution

Is conducted to identifieed the systems behavoure for longer
execution times. memory leaks and buffer over flows r
usaually identified through the testing.

 Suneel Reddy's answer is absolutely wrong

Testing is done with expected user load sustained over 
longer period of time with normal ramp up and ramp down 
time ; Identify Memory Leaks

Example:
 Checks for memory leaks or other problems that may occur 
with prolonged execution. (A memory leak occurs when the 
memory allocated to objects are not being freed by the 
application, and hence the system memory continues to be 
used up when the application is run over a prolonged period 
of time, until the point at which it breaks down due to 
lack of memory

There are 4 types of performance testing:
1. Load: Determines response times of critical business
processes and transactions to determine whether they are
within documented expectations 
2. Volume: Determines throughput associated with a specific
process or transaction. Determines the capacity drivers
associated with a specific process or transaction
3. Stress: Determines the load under which a system fails,
and how it fails 
4. Longevity and endurance: Identifies performance problems
that may appear after a system has been running at a high
level for an extended period of time