```html

Differences Between White-box Testing and Black-box Testing

White-box testing and black-box testing are two distinct approaches to software testing with different methodologies and purposes.

White-box Testing

White-box testing, also known as clear-box or glass-box testing, is a testing technique where the tester has access to the internal structure and code of the software being tested. It focuses on verifying the internal logic and paths within the software.

Example: Unit tests are a common form of white-box testing, as developers write test cases to examine and ensure the correctness of individual components or functions within the codebase.

When to use: White-box testing is most appropriate during the development phase of a software project to validate the correctness of code implementations and detect any logical errors or bugs early in the process.

Black-box Testing

Black-box testing, also known as functional or behavioral testing, is a testing technique where the tester assesses the functionality of the software without knowing its internal workings. It focuses on validating the software against specified requirements and inputs.

Example: User acceptance testing (UAT) is a form of black-box testing where end-users or stakeholders evaluate the software's functionality based on their expectations and requirements.

When to use: Black-box testing is most suitable during the later stages of the software development lifecycle, such as system testing or acceptance testing, to ensure the software meets the desired user experience and functional requirements.

```
This HTML snippet provides an SEO-friendly answer to the question, highlighting the differences between white-box testing and black-box testing and when to use each approach in a software development project.