Design Control is a broad definition of illustrating how you monitor the design process before it goes to the FDA for auditing. There are overall 9 files that should be accomplished: Planning, Input, Output, Review, Verification, Validation, Transfer, Design Changes, and Design History File.
From the perspective of a company, this is a very necessary thing to start with when you wish to develop a new product whose function is consistent with your design, the demand from the market, and no moral issues. From the official organizations such as NIH or FDA, the design control has to be formally assessed for every new applications to ensure the safety use and verification.