Perun is a very old god that people used to worship a long, long time ago. He was very important to some people who lived in a place called ancient Slavic lands. They believed that Perun had very strong powers and could control the weather and lightning.
People thought that Perun was a really powerful god because he could make loud thunder and lightning with his special tools like an axe and lightning bolts. They believed that whenever there was a big thunderstorm, it was because Perun was angry or needed to fight a bad spirit.
People would ask Perun for help when they needed it, like when they had trouble with their crops or were scared of a big storm. They would have special ceremonies and they made offerings to him like food or flowers, hoping that Perun would listen to them and help them out.
Perun was really important to these people and they really believed in him. Even though not very many people worship Perun anymore, his story and influence still lives on, and he remains an important part of Slavic mythology.