Okay kiddo, let's talk about the names of Beijing. Beijing is a very big city with a very long history, so it has had many different names throughout the years.
The first name you need to know is "Ji", which was the original name of the city. People started living there a long, long time ago – even before people started writing down history – and they called it "Ji".
After that, different groups of people came and went, and they gave the city new names. One group called it "Yanjing", which means "capital of Yan". Yan was the name of an ancient kingdom that existed a long time ago.
Over time, the people who lived in Yanjing became more powerful, and they started their own dynasty – the Jin Dynasty. When they did that, they changed the name of the city again, this time to "Zhongdu", which means "central capital".
After the Jin Dynasty, another dynasty came along: the Mongols. They took over the city and made it their own capital, and they called it "Dadu", which means "great capital".
Eventually, the Mongols were replaced by the Ming Dynasty, and they changed the name of the city to "Beijing", which means "northern capital". That is the name that the city still has today.
So, there you have it – the story of how Beijing got its name. It's gone by many different names over the years, but today it is known as "Beijing", and it's one of the biggest and most important cities in China.