add image ref

Author: TvisharajiK

versioned_docs/version-2.0.0/concepts/reference/glossary/functional-testing.md

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 Functional testing is a type of software testing that verifies that the software system or application behaves according to the specified functional requirements and meets the intended business needs. It focuses on ensuring that the system's features, capabilities, and interactions with different components work as expected.
 
 Functional testing is typically performed by providing the software with input data and then checking the output data to see if it matches the expected results. This can be done manually or using automated testing tools.
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+  ## Types of Functional Testing
+  <div align="center">
 
-## Types of functional Testing
 
-![types of testing](../../../../../static/img/glossary/ft.png)
+  ![types of testing](../../../../../static/img/glossary/ft.png)
 
+  [Functional Testing](https://keploy.io/blog/community/functional-testing-unveiling-types-and-real-world-applications)
+
+</div>
 There are many different types of functional testing, including:
 
 ### 1. Unit Testing