I have heard of this term many times (in the context of programming) but couldn't find any explanation of what it meant. Any good articles or explanations?
I think you're referring to test fixtures:
The purpose of a test fixture is to ensure that there is a well known and fixed environment in which tests are run so that results are repeatable. Some people call this the test context.
Examples of fixtures:
- Loading a database with a specific, known set of data
- Erasing a hard disk and installing a known clean operating system installation
- Copying a specific known set of files
- Preparation of input data and set-up/creation of fake or mock objects
(source: wikipedia, see link above)
Here are also some practical examples from the documentation of the 'Google Test' framework.