Mandaeanism is a religion that some people follow. The people who follow this religion are called Mandaeans.
Mandaeans believe in many things that are different from what other religions believe. They believe in a god named Hayyei, who they think created the world. They also believe that every person has their own spirit, and that this spirit can help them understand the world better.
One really special thing about Mandaeans is that they think water is really important. They believe that God created everything in the world to be perfect and balanced, and water is the most important thing to help keep that balance. Because of this, they practice baptism often.
In their religion, they have special people called "Mandaiia" who are kind of like religious leaders. These people are really important because they help other Mandaeans learn and follow their religious beliefs.
Overall, Mandaeanism is a religion that has its own unique beliefs and practices. It may be different from what you've heard before, but for Mandaeans it's just as important as any other religion is to its followers.