Several software testing experts are of the firm opinion that "software testing affirms the quality of the software with methods that can be economically and effectively applied to both large and small systems."[1]

 Program testing cannot assure a program's correctness but it can indicate the presence of "bugs." In order to test a program, input is required so that the program may be executed in a desired way. Typical software testing involves two individual tests of software modules. One is to test program's structure when the other one is to develop series of tests that affirm the the actual content of the software system. The most common application of program testing also involves analyzing when either individual programs or major parts of larger systems are finished . This means the software is stable enough so that the majority of mistakes have been found and removed.

 Software testing ensures the reliability of the software, and the safety of the people who utilize the operations of the program. A number of software testing techniques are currently in use:

• Black-box, or functional, testing
• White-box testing
• Unit testing

1. Howden, W.E, and E. Miller. Software Testing & Validation Techniques , IEEE Computer Society, New York, 1981