Behat vs JUnit comparison of testing frameworks
What are the differences between Behat and JUnit?

Behat

https://docs.behat.org/en/latest/

JUnit

https://junit.org/junit5/
Programming language

PHP

Java

Category

Functional/Acceptance Testing

Unit Testing, Regression Testing

General info

Behat is an open source Behavior-Driven Development framework for PHP.

Behat uses the StoryBDD subtype of behaviour-driven development (the other subtype is SpecBDD); This means the tests we write with Behat look rather like stories than code. It is inspired by Ruby's Cucumber

JUnit is an open source Unit testing framework for java

JUnit is useful for developers to write and run repeatable tests. JUnit has been crucial in the development of test driven development and is partof the xUnit family of unit testing frameworks
xUnit
Set of frameworks originating from SUnit (Smalltalk's testing framework). They share similar structure and functionality.

No

Yes

It is an instance of the xUnit architecture for unit testing frameworks.
Client-side
Allows testing code execution on the client, such as a web browser

Yes

To enable Behat to test a website, you need to add Mink and a browser emulator (selenium maybe, though slow) to the mix. Mink methods are the connector between Behat and an extensive list of available drivers, and they provide a consistent testing API.

Yes

You can test front-end components such as individual classes and functions that create the front-end
Server-side
Allows testing the bahovior of a server-side code

Yes

Behat can be used for Data Integrity Testing to verify that database operations are functioning properly

Yes

You can test classes and functions that compose the back-end such as database connections and so on
Fixtures
Allows defining a fixed, specific states of data (fixtures) that are test-local. This ensures specific environment for a single test

Yes

One can use the 'Doctrinefixturesbundle' to create the required fixture loaders and load them in our Behat scenarios when required, using the 'BeforeScenario' hook.

Yes

JUnit contains a setUp() method, which runs before every test invocation and a tearDown() method, which runs after every test method.
Group fixtures
Allows defining a fixed, specific states of data for a group of tests (group-fixtures). This ensures specific environment for a given group of tests.

Yes

Behat allows for group fixtures

Yes

You can use setUp() and tearDown() inbuilt functions as group fixtures.
Generators
Supports data generators for tests. Data generators generate input data for test. The test is then run for each input data produced in this way.

By use of third party libraries like moodle-behat-generators

You can use JUnit-quickcheck to generate test data
Licence
Licence type governing the use and redistribution of the software

MIT License

Mocks
Mocks are objects that simulate the behavior of real objects. Using mocks allows testing some part of the code in isolation (with other parts mocked when needed)

By using third party libraries like Mock and Prophecy

JUnit does not support mocking internally but you can use a mock framework like Mockito to generate mock objects.
Grouping
Allows organizing tests in groups

Yes

You can use tags to group features and scenarios together, independent of your file and directory structure

Yes

In JUnit you can create a test suite that bundles a few unit test cases and runs them together. You use both @RunWith and @Suite annotation are used to run the suite test.
Other
Other useful information about the testing framework