Continuous integration is a process of collaborating the code into the mainline code base. In simple words, continuous integration helps developers to test their new code at the initial stage by creating frequent builds while they are developing and generating test results, and if everything works, then merging the code to the mainline code.

This can be understood by the following diagram, which depicts the issues that occur during SDLC:

There are, basically, the following types of issues that occur during continuous integration:

• Build failure before integration
• Integration failures
• Build failure (after integration)

In order to solve those issues, the developer needs to modify the code to fix it, and the complete integration process is repeated again until the feature is successfully deployed.