What is Testing?

Software systems are an integral part of our daily life. Most people have had experience with software
that did not work as expected. Software that does not work correctly can lead to many problems,
including loss of money, time or business reputation, and, in extreme cases, even injury or death.
Software testing assesses software quality and helps reducing the risk of software failure in operation.

Software testing is a set of activities to discover defects and evaluate the quality of software work
products. These work products, when being tested, are known as test objects. A common misconception
about testing is that it only consists of executing tests (i.e., running the software and checking the test
results). However, software testing also includes other activities and must be aligned with the software
development lifecycle (see chapter 2).

Another common misconception about testing is that testing focuses entirely on verifying the test object.
While testing involves verification, i.e., checking whether the system meets specified requirements, it also
involves validation, which means checking whether the system meets users’ and other stakeholders’
needs in its operational environment.

Testing may be dynamic or static. Dynamic testing involves the execution of software, while static testing
does not. Static testing includes reviews (see chapter 3) and static analysis. Dynamic testing uses
different types of test techniques and test approaches to derive test cases (see chapter 4).
Testing is not only a technical activity. It also needs to be properly planned, managed, estimated,
monitored and controlled (see chapter 5).