Software testing is more than just error detection;

Testing software is operating the software under controlled conditions, to (1) *verify* that it behaves "as specified"; (2) to *detect* *errors*, and (3) to *validate* that what has been specified is what the user actually wanted.

1. *Verification* is the checking or testing of items, including software, for conformance and consistency by evaluating the results against pre-specified requirements. [*V**erification: Are we building the system right?*]

2. *Error Detection*: Testing should intentionally attempt to make things go wrong to determine if things happen when they shouldn't or things don't happen when they should.

3. *Validation* looks at the system correctness – i.e. is the process of checking that what has been specified is what the user actually wanted. [*Validation: Are we building the right system?*]

In other words, validation checks to see if we are building what the customer wants/needs, and verification checks to see if we are building that system correctly. Both verification and validation are necessary, but different components of any testing activity.

The definition of testing according to the ANSI/IEEE 1059 standard is that testing is the process of analysing a software item to detect the differences between existing and required conditions (that is defects/errors/bugs) and to evaluate the features of the software item. Remember: The purpose of testing is verification, validation and error detection in order to find problems – and the purpose of finding those problems is to get them fixed.

Software Testing

Testing involves operation of a system or application under controlled conditions and evaluating the results. Every Test consists of 3 steps :

Planning : Inputs to be given, results to be obtained and the process to proceed is to planned.

Execution : preparing test environment, Completing the test, and determining test results.

Evaluation : compare the actual test outcome with what the correct outcome should have been.