A floating license allows multiple users access to a product, but each license can be used by one user at a time.
You can think of floating licenses like a book at a library. Different people can check out access to the book, but only one person can have the book at a time. While someone has the book nobody else can access it. Once the book is returned a different person can access the book.
Floating accounts are also used for accessing ReadyAPI in a CI/CD pipeline or when using ReadyAPI products in a containerized environments such as Docker.