What is a REAL ID?
After the terrorist attack on 9/11, the government identified a major issue with DMVs across the country. They were not collecting adequate identity information when issuing photo IDs and driver licenses. A set of reforms was put into place including REAL ID. Obtaining a REAL ID requires you to present additional identity information to secure your government photo  ID.
 
Why should I get one?
Beginning October 2020, a REAL ID will be required to access Federal facilities, enter nuclear power plants, and, board federally regulated commercial aircraft.

How do I get one?
You may already have one. Many states implemented the REAL ID requirements early. Check your license for a gold star or contact your local DMV to confirm if you have a REAL ID. If you don't, your local DMV should be able to issue one. Be sure to specify that you want a REAL ID. It may have an additional fee.

Do I need a separate REAL ID if I have an Enhanced Driver’s License or Passport?
People who live in border states may have the option to get an Enhanced Driver’s License. This allows passage between the US and Mexico and Canada by land. This counts as a REAL ID. A passport is also a REAL ID. I personally got a REAL ID driver’s license in addition to my passport so I don’t have to take my passport on flights within the United States.