What are the differences and connections between hummingbirds and kingfishers?

Hummingbird is the smallest bird in the world, mainly distributed in America. They can stay in the air or fly backwards. They feed on nectar, and some prey on insects. Hummingbirds are mostly brightly colored and metallic. Kingfisher belongs to the family Kingfisher, which is divided into aquatic kingfisher and forest kingfisher, mainly distributed in Australia, Asia, Africa and Europe. Living on reeds and branches near the pond, it has bright blue feathers on the back and face, chestnut belly, light horizontal spots on the head, and red mouth and feet. It feeds on fish and insects.