Exploratory Testing is an approach to software testing
that is concisely described as
simultaneous learning, test design, and test execution.
Cem Kaner, who coined the term in 1984, defines exploratory testing as:
"a style of software testing that emphasizes the personal freedom and
responsibility of the individual tester to continually optimize the
quality of his/her work by treating test-related learning, test design,
test execution, and test result interpretation as mutually supportive
activities that run in parallel throughout the project."