Levels of Testing in Software Testing

Tests are generally classified on where they are implemented in the SDLC or the degree of information they include. There are four types of testing overall: unit testing, integration testing, system testing, and acceptance testing. The goal of Levels of testing is to make software testing more methodical and to make it easier to discover all feasible test scenarios at a given level.

There are several testing tiers available to aid in the evaluation of software behavior and performance. These testing stages are intended to identify gaps and reconcile the development lifecycle phases. SDLC models define stages such as requirement gathering, research, designing, programming or implementation, testing, and installation. Every one of these stages goes through the software testing stages procedure.

Levels of Testing

In software testing, there are four stages of testing −

  • Unit testing − It determines whether or not software components meet their functionalities.

  • Integration testing − It involves examining the flow of data from one unit to another.

  • System testing − It examines both functional and non-functional testing requirements.

  • Acceptance testing − It ensures that the requirements of a specification or agreement are satisfied in accordance with its execution.

Each of these stages of testing has a distinct function. These levels of testing contribute positively to the software development process.

Unit Testing

A unit is the smallest tested component of an application or system that can be built, configured, loaded, and run. This type of testing aids in evaluating each component independently.

The objective is to evaluate each component of the software separately. It determines whether or not a part fulfills its responsibilities. Programmers are in charge of this type of testing.

Integration Testing

Integration is the process of merging two or more things. In this testing step, for instance, separate software units are joined and evaluated as a group to ensure that the integrated system is ready for system testing.

Integrating testing ensures that data flows from one component to the next. This type of testing is carried out by testers.

System Testing

System testing is carried out on a comprehensive system. It allows you to examine the system's compliance with the standards. It examines the entire interplay of the elements. Capacity, efficiency, stability, and security testing are all part of the process.

System testing is frequently used as the final check to ensure that the system satisfies the specifications. It assesses both functional and nonfunctional testing requirements.

Acceptance Testing

Acceptance testing is a procedure used to determine whether or not the criteria of a spec or agreement have been satisfied as of the delivery time. The clients or consumer does acceptance testing. Other shareholders, however, may be involved in the decision.

Other Types of Testing

  • Regression Testing

  • Buddy Testing

  • Alpha Testing

  • Beta Testing


  • A level of software testing is a method that tests each unit or component of a software/system.

  • The fundamental purpose of system testing is to determine if the system meets the requirements.

  • Unit testing, integration testing, system testing, and acceptance testing are the four primary layers of testing in software engineering.