Probably not asked often enough, DO-160 is a ‘means to compliance’. Rather than a standard or requirement, it is an agreed upon path to satisfy requirements for Title 14 Parts, 23 (Commuter), 25 (Transport) and 27 (Rotorcraft) for electronic equipment.
If your equipment must satisfy any of those Parts of Title 14, and the testing is performed in accordance with DO-160, the FAA agrees to accept the results.
This is an enormous time saver. Rather than develop a test methodology and then convince the certification authorities that your methodology is sufficient to demonstrate compliance, the work is already done.
While the process is not that simple it is that straight forward.
Throughout this site are the resources to help you accomplish this.