Exploratory testing

(ET) Exploratory testing is an approach towards testing. It involves concurrently learning, designing, and executing, and recording tests, at the same time rather than specifying all your tests upfront before execution, and it has the purpose of uncovering information related to risks.
 

I could do things like explore different types of data that could be submitted via a web form or explore the rendering of a web page across multiple browsers or explore how a feature works depending on different user privileges.
 

Exploratory testing empowers, testers to use their skills to discover information freely. ET can be structured to help keep the tester focused on specific risks, and it can help, a tester to reveal more information that a scripted test approach wouldn't uncover as you're not biased by the test case steps.
 

Exploratory testing is an approach that requires a lot of skill and practice. A good exploratory tester needs to know how to focus and defocus when testing, And note taking is important to help communicate what a tester has done whilst not hampering them, but this is hard to do.

Exploratory testing provides the organised feel of scripted testing with the rapid feedback of ad-hoc "try-to-break-it" testing. Identifying what to test next is where exploratory testing comes into its own – by using structure and fast feedback.

Exploratory testing is a human-led approach that brings creativity, intuition, and adaptability to uncover issues that structured tests might miss. It allows testers to learn about the system, identify risks, and discover unexpected behaviours that structured tests might miss. 

For example, when testing a mobile shopping app, a tester might explore different input methods, e.g. typing, voice search, or barcode scanning, while adapting their approach based on observations.