Multiline Strings (also known as PyStrings) are useful for specifying a larger piece of text. The inspiration for PyString comes from Python where """ is used to describe docstrings. PyString concept is exactly same as Cucumber Doc String. So, in Cucumber you will find Doc String instead of PyString.
Behat is an open source Behavior Driven Development tool. It's a PHP framework for auto testing your business expectation. With BDD, you write human-readable stories that describe the behaviour of your application. These stories can then be auto-tested against your application.