"Pedaresty" was a big word for ancient Greeks. It means an adult man having a special relationship with a young boy. Greeks saw it as a cultural norm and romanticized it. For them, relationships between adult men and young boys were things that they saw as a rite of passage. Aristotle, a famous Greek philosopher, wrote that it was necessary to educate the boys in the way of the world by teaching them about love.
Usually, pedaresty meant an older man taking a younger boy (around 12-18 years old) under his wing and teaching them things about being an adult, like hunting or fighting. However, some relationships became sexual or romantic. Greeks believed that boys were too young to fall in love with women.
In ancient Greece, men were allowed to have sex with other men as long as the partner was considered lower in status, like a slave or a boy. It was taboo to have sex with someone considered equal in status. They believed that sex between a man and a boy wasn't wrong because the boy wouldn't be able to give birth to children, and since that was what was expected of women, that made it different.
Today, we know that this type of relationship is considered harmful because it often leads to the psychological problems of the young boys involved. Therefore, most countries have made laws against such relationships.