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

	Cucumber https://github.com/cucumber/cucumber-ruby	JUnit https://junit.org/junit5/
Programming language	Ruby	Java
Category	Acceptance Testing	Unit Testing, Regression Testing
General info	An automation tool for Behavior-Driven Development The specifications are written in plain texts, which allows them to be easily understandable for all stakeholders. Cucumber Framework also supports languages beyond Ruby e.g. Java, JavaScript and Scala.	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 You can test the front-end part like the GUI using cucumber and selenium, they integrate well to test your front-end.	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 You can test back-end components such as APIs using rest & soap clients, and databases using whatever client libraries were provided by the libraries that existed in those stacks	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 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 Using the cucumber extension aruba you can create fixures in two steps: 1.Create a fixtures-directory; 2.Create fixture files in this directory	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.	Yes You can group your fixtures inside your fixtures directories	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)	Yes By using all of RSpec’s supported mocking frameworks (RSpec, Mocha, RR, Flexmock)	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 Cucumber allows the use of tag Cucumber feature files or individual tests to group tests. Then, you can pass a Cucumber tagged expression at test execution that specifies the tag (grouped) tests to run. https://www.toolsqa.com/cucumber/cucumber-tags/	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