Traditionally, the lead is in charge of the entire structure of the dance. The lead must give the follow clear instructions. Traditionally, the follow has limited choices, and all choices must mesh with the lead’s instructions.
First, the traditional definition is literally inaccurate. Of course you can dance that way. But the best dancers do not. The best dance partnerships work as a team, both people contributing creative ideas on the fly, each responding to the other’s movements, adapting the direction of the dance based on their partner’s input.
This is a must-read article on the subject of connection in dance. One of the biggest breakthroughs in my own dancing came when I realized that the lead can initiate a movement that the follow then completes. How a follow chooses to move in response to the lead is where much of their creativity is expressed. This movement then influences how the lead subsequently moves, and the cycle continues.
The best dances I have occur when ideas flow back-and-forth seamlessly. The distinction between leading and following disappears, and the dance becomes about two people together weaving something beautiful out of the music and movement they share. Yin & Yang. Lead & Follow.