Okay kiddo, so you know how we all believe different things and follow different rules? Well, the same thing happened to the Jewish people a long time ago. They had different ideas about how they should follow their religion and this led to something called a "schism".
Some people believed that they should follow the rules exactly as they were written in the Torah (which is a holy book for them), while others thought it was okay to change some things to fit the current times. This caused a big argument and eventually, the Jewish community split into different groups.
One of these groups became known as the "Sadducees" who believed in following the rules very strictly, while another group called the "Pharisees" thought it was okay to interpret the rules to fit the new world they lived in. Over time, more and more groups formed with different beliefs and practices.
This led to different sects or branches of Judaism. Some of these include Reform Judaism, Conservative Judaism, and Orthodox Judaism. They all worship the same God, but they have different beliefs about how they should follow their religion, what they should wear, and what they should eat.
In the end, it's all about respecting each other's beliefs and finding a way to live in peace even with our differences.