Scientifically, the bright patch of light is the result of looking at a concentrated band of billions of different stars in our galaxy. When we look up at the night sky, we are viewing the galaxy on its side. This view creates the glowing arc of light that we know as the Milky Way galaxy.Other cultures have different names for the Milky Way. In Germany, the galaxy is called “Milchstrasse” and Norwegians call the galaxy “Melkeveien.”
The romans named it via lactea precisely bcoz its looks like a milky patch of sky above the earth at night. But the Romans weren't the first to name the galaxy . The Romans got the name from the Greeks who called it galaxias kyklos, which translates into "milky circle"