Robocall from carpet cleaning service telling about specials.

Received a call today on cell phone no messa.ge left

What is a do not call list for

Called about 6:30pm.  Didn't recognize it so I didn't answer.  No message left.

Unknown caller attempted to contact me via cell phone. Because the calling # is not in my contacts list the call was dumped (I chose the app for this very reason - dump the call but record the 'number' and let me investigate afterwards). The area code is from northern MI but the odds are slim to none that a carpet cleaner would travel that far just to clean my carpets ...