Types of Software Testing
Updated: May 9, 2021

Software Testing
Software testing is an integral and most critical part of the software development life cycle (SDLC). In today's age, there is software for every possible human need. It is important for software professionals to understand what are the different ways to test software to improve not only the functional quality of the software but also the non-functional and aspects of the software. The tester can follow different approaches to test the software, let's learn about all these possible approaches in detail.
The diagram below represents a hierarchical view of various types of testing a tester can perform on the software. This is not an exhaustive list but covers the most popular software testing types.
Software Testing Types

Software Testing level v/s Software Testing type
Before moving forward, it is important to understand the difference between a test level and the test type.
Software Test levels are the stages of testing like Unit testing, Component testing, Integration Testing, System Testing, and User Acceptance testing a software goes through till it reaches the end-user.
Whereas software testing types are different ways we can test software. Examples of testing types are black box, white box, grey-box testing types. In general, a tester performs different types of testing within the same testing level. A testing level can have white-box and/or black-box and/or grey-box software testing types implemented to thoroughly test the system
Learn - Software Testing Levels v/s Software Testing Types
Three software testing types -

Black Box Testing
White Box Testing
Grey Box Testing
Follow the below section to get an in-depth understanding of all three software testing types -
1. Black Box Testing -
Black Box testing is based on testing without going into the code rather than running the executable and treating the system as a black-box. Testing is done from an end-user perspective without worrying about how code is written, its design, etc. This type of software testing technique examines the functionality of the software as a black box without knowing internal code structure, internal paths, and implementation details. It mainly focuses on the input conditions and output behavior of software applications and the goal is to test software as per functional and non-functional requirements.

Black Box Testing can be further divided into two types
Functional Testing
Non-functional Testing
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2. White Box Testing -
White box testing is the technique that tests the
internal structure,
design,
code structure, and
data structure
of the software application. This technique is also called structural testing, clear box testing, open box testing, and transparent box testing. The goal of testing is to improve architecture design and optimize the code and data structure of the software. It also helps strengthen the security of the software.
White-box can be performed using below testing methods -
Statement Coverage
Decision Coverage
Branch Coverage
Condition Coverage
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3. Grey Box Testing
A proportionate combination of White Box and Black Box Testing, Grey Box Testing is performed with partial knowledge of the internal structure of the application and limited knowledge of the functionality of the system. Grey box testing involves access to internal coding like in white box Testing. Functional testing is done using Black-box testing techniques. As a hybrid method, it is found to be better when code is not developed completely and not all functionality is available to test. Hence grey box testing can start early in SDLC. It is most commonly used to search and identify defects due to improper code structure. It improves the testing coverage by concentrating on all layers of a complex system.
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Learn Advance - Best Practices In Software Testing (Automation & Manual Testing)