Difference between Unit Testing and System Testing
Last Updated :
06 Jan, 2025
Unit testing involves testing individual components of software in isolation to ensure they function correctly, primarily by developers using automated test frameworks. It focuses on early bug detection and code quality improvement. On the other hand, system testing checks the integrated software system as a whole, validating its functionality against specified requirements, typically performed manually by testers in a production-like environment to ensure overall system readiness.
What is System Testing?
System testing is done to check whether the software or product meets the specified requirements or not. It is done by both testers and developers. It contains System testing and Integration testing. It is done through more positive and negative test cases.
What is Unit Testing?
Unit Testing is the type of software testing level in which each component of the software is tested. Unit Testing is generally performed by the developer. Unit Testing can’t be used for those systems which have a lot of interdependence between different modules. It does not allow for parallel testing.
It focuses on testing individual components or functions of a software application, ensuring they work in isolation. In contrast, system testing validates the complete integrated software system, ensuring that all components work together as expected in real-world scenarios.
Difference Between Unit Testing and System Testing
| Aspects | Unit Testing | System Testing
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| Scope of testing | Tests individual units or components of the software application in isolation | Tests the complete system or software application
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| Timing of testing | Typically automated and performed by developers during the coding phase | Typically manual and performed by independent testers after the completion of integration testing
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| Focus of testing | Focuses on verifying the functionality of each unit or component of the software application | Focuses on verifying the functionality of the system as a whole
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| Testing environment | Tests are executed in a controlled environment, typically using mock objects or test doubles to isolate the unit being tested | Tests are executed in a production-like environment to simulate real-world usage scenarios
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| Testing frameworks | Uses unit test frameworks such as JUnit, NUnit, or PHPUnit to automate the testing process | Uses system testing frameworks such as Selenium, HP UFT, or IBM Rational Functional Tester to automate the testing process
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| Purpose of testing | Enables early detection and elimination of defects in the code | Enables validation of the entire software application to ensure it meets the specified requirements |
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| Skills required | Requires a solid understanding of the code and the ability to write effective test cases | Requires a comprehensive understanding of the software application and the ability to write effective test cases
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| Feedback | Provides fast feedback on the quality of individual units or components | Provides a comprehensive understanding of the quality and readiness of the entire software application |
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| Execution | Typically executed by developers in a continuous integration and delivery (CI/CD) pipeline | Typically executed by independent testers in a separate testing environment
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| Types of testing | Tests for both functional and non-functional aspects of the software application | Tests for both functional and non-functional aspects of the software application, including performance, security, and usability testing |
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