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

	Cucumber https://github.com/cucumber/cucumber-ruby	NUnit https://nunit.org/
Programming language	Ruby	.NET
Category	Acceptance Testing	Unit 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.	NUnit is an open-source unit testing framework for Microsoft .NET. NUnit was Initially ported from JUnit. Tests can be run from a console runner, within Visual Studio through a Test Adapter or through 3rd party runners. Tests can be run in parallel and has Strong support for data driven tests. Unit supports multiple platforms including .NET Core, Xamarin Mobile, Compact Framework and Silverlight.
xUnit Set of frameworks originating from SUnit (Smalltalk's testing framework). They share similar structure and functionality.	No	Yes Nunit is one of many programs in the xUnit family
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 with NUnit since it is a Unit testing framework the application is isolated into diverse modules which are tested independently
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 back-end components with NUnit, it is a Unit testing framework hence the application is isolated into diverse modules which are tested independently
Fixtures Allows defining a fixed, specific states of data (fixtures) that are test-local. This ensures specific environment for a single test		Yes NUnit contains the fixture methods SetUp to initialize your test environment and TearDown method to destroy a test environment
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 Group fixtures are available in NUnit
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	N/A
Licence Licence type governing the use and redistribution of the software	MIT License	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)	Yes You can create mock objects using the third party library moq
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 You can group tests into suites with NUnit
Other Other useful information about the testing framework