What are the similarities between a tadpole and fish? What does this confirm?

Tadpoles are essentially frog larvae. At first, tadpoles have little resemblance to frogs, since, like fish, they hatch from eggs, and their heads and tails are very similar to fish ones. This fact indicates that, most likely, fish and frogs had common ancestors, which evolved over millions of years and divided into several species. At later stages of development in tadpoles, first one pair of legs grows, then another, then the tail falls off, and no trace remains of the resemblance to fish.