Why do undemocratic nations name themselves "Democratic Republic"?

Communist countries such as North Korea and Laos have the goal of a democratic economy. Their goal is to control and run the economy for the benefit of all their people. It is difficult to determine if these Communist countries have reached these goals.

In the last few years, The Democratic Republic of Congo has conducted elections and has created a Constitution. The history of the Congo shows dictatorship and the country may return to dictatorship.

It sounds better than the authoritarian regime of wherever