The Walloon Church is a type of Christian church that started a very long time ago in a place called Belgium. It's called "Walloon" because that is the name of the people who started it. These people were French-speaking, and they wanted to have a church where they could worship in their own language.
The Walloon Church grew and spread to other places beyond Belgium. For a while, it was very popular in other countries like the Netherlands, England and the United States. The people who went to the Walloon Church were usually very smart and educated, so they liked to discuss important things like religion, politics and philosophy.
Today, there are still some Walloon Churches in different parts of the world, but they are not as well-known as they used to be. Some people still like to go to these churches because they feel connected to the history and traditions of the Walloon people. Others might go just because they like the way they worship or because they think it's interesting to learn about something new.