Okay, kiddo, so a long time ago, there was a man named Quirinius who worked for the government. He was in charge of counting all the people who lived in a certain place, kinda like if I asked you to count all the toys in your room.
So Quirinius went around to every house and asked how many people lived there. He wrote down each answer to figure out how many people there were in total. This was called a "census."
Now, some people think that this census of Quirinius is important because it is mentioned in a story about a special baby named Jesus who was born a long time ago. His parents had to travel to a different town because of the census, and that's where Jesus was born!
So the census of Quirinius is a way for people to remember the story of Jesus' birth and how important it was. And it's also a way for us to learn about how the government used to count people a long time ago.