A "white box" refers to a type of testing or analysis where the internal workings of a system are known and accessible. This approach allows testers to examine the code, algorithms, and logic behind a software application, making it easier to identify potential issues or vulnerabilities. It contrasts with "black box" testing, where only the inputs and outputs are considered without knowledge of the internal processes. In software development, white box testing is often used to ensure code quality and functionality. It can involve techniques such as code coverage analysis and unit testing, which help developers like programmers and software engineers verify that each part of the code performs as intended.