What is the difference between Stress Testing and Load Testing?

“Stress Testing” is subjecting a system to an unreasonable load while denying it the
adequate resources as required to process that load. The resources can be RAM, disc space,
mips & interrupts etc. etc. The idea is to stress a system to the breaking point in order to
find bugs, which will make the break potentially harmful. The system is not expected to
process the overload without adequate resources, but to fail in a decent manner (e.g.,
failure without corrupting or losing data). In stress testing the load (incoming transaction
stream) is often deliberately distorted so as to force the system into resource depletion.

Whereas “Load Testing” is a test performed with an objective to determine the maximum
sustainable load which the system can handle. Load is varied from a minimum (zero) to the
maximum level the system can sustain without running out of resources or causing
excessive delay in transactions.