Hosts connect talent and venues, and raise awareness about such gatherings as concerts, performances, speaking tours and more. Think of them as a producer of the event or an event planner.
They could be an owner of a restaurant, a performance space, or a yoga studio. They might have an online following and are looking for speakers to engage and entertain their community.
They can be a principal looking for someone to lead a class for their students.
The sky is the limit.