Take an arbitrary piece of hardware; As part of the Product Lifecycle Management the manufacturer has a complete trace to the individual versions of all the components that went into it.

Application Lifecycle Management means that you apply the same approach to software. You trace everything.

The requirements that created the tasks, the commits that resolved them, the compiler that built them, the tests you ran, the environment you ran them in, the test results and so on. When the software reaches production, you know the specifics of everything that created it.