My definition of Exploratory Testing
Exploratory testing involves a tester using their knowledge and experience to explore a website or app, learn it’s layout, contents and functions whilst simultaneously designing and executing test scenarios and test cases. This unscripted approach can lead to issues being found almost immediately.
Wikipedia definition of Exploratory Testing
Exploratory testing is an approach to software testing that is concisely described as simultaneous learning, test design and test execution.
http://en.wikipedia.org/wiki/Exploratory_testing
Cem Kaner’s (and others) definition of Exploratory Testing
“Exploratory software testing is a style of software testing that emphasizes the personal freedom and responsibility of the individual tester to continually optimize the value of 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.”
http://kaner.com/?p=46
Michael Bolton’s definition of Exploratory Testing
“simultaneous (or parallel) test design, test execution and learning”
http://kaner.com/?p=46#comment-26
Video
Exploratory Testing playlist on YouTube