What does Continuous Integration (CI) in software development involve?

Continuous Integration (CI) in software development is primarily about the frequent testing and merging of code changes. This practice is essential for maintaining code quality and ensuring that new code integrates smoothly with the existing codebase. By frequently merging updates, developers can identify issues early in the development cycle, which helps to reduce integration problems and enable teams to deliver features faster. CI typically involves automated tests that run whenever code is merged, creating a feedback loop that allows developers to address issues quickly.

User manuals, stress testing applications, and prolonged code freeze periods do not align with the principles of Continuous Integration. Writing comprehensive user manuals is more related to documentation, while stress testing focuses on assessing application performance under heavy loads. Prolonged code freezes are contrary to the CI approach, as they imply halting development activities rather than promoting continuous integration and delivery. Thus, the answer correctly captures the essence of what Continuous Integration entails.