Why can be tester dependent on configuration management?

Configuration management is a topic that often confuses new practitioners. So, let me describe it briefly: Configuration management determines clearly about the items that make up the software or system. These items include source code, test scripts, third-party software, hardware, data and both development and test documentation.

Exactly in the upcoming technologies like salesforce we testers are fully on configuration management.

Because configuration management assures that we know the exact version of the testware and the test object.