Licensing options for tableau server and tableau online
Tableau server can be licensed in two different ways:
Server core license
Core licensing provides unlimited access to any number of users, pricing is based on the number of processor cores contained on the physical box or multiple boxes on which you deploy the software per-named-user licensing starts with a minimum of ten users. Core licensing requires an eight-core minimum. Although many factors can affect performance in a server deployment (hardware, network traffic, dashboard design), an eight-core configuration can support up to 225 concurrent users.
Tableau online is a named-user license that requires a one-year commitment. You can start with a single license and add more as your needs grow.