Vanir are a group of gods from Norse mythology. Think of them like a group of superpowerful beings who have special abilities and control different aspects of nature. These gods were worshipped by the Vikings and Scandinavians a long time ago.
Now, imagine that there are two groups of gods - the Vanir and the Aesir. They were enemies at first, but later decided to make peace and work together. The Vanir gods have powers over things like fertility, growth, love, and the earth, while the Aesir gods have powers over things like war, death, and the sky.
Some of the most famous Vanir gods are Freyja, the goddess of love and fertility, and her brother Freyr, who also has powers over farming and growth. Another important Vanir god is Njord, who controls the wind and sea.
Overall, Vanir are a group of powerful Norse gods who are worshipped for their abilities to control different aspects of nature.