Hi Sai. Starting with 2018.1, the servers have become much more peers of one another rather than the old primary / worker paradigm. In other words, you start with server 1, and install the TS software here. Then you install the bootstrap files generated off of the initial server install on server 2 through server x. The major change in architecture is that you're no longer locked into a primary + x workers, but rather if the initial server (that has associated licensing checks) has problems, then you can reassign the responsibilities to one of the other nodes.
Does this help, does it make sense?
As Jeff suggested, you can install multiple Tableau servers without dealing with Primary and worker node.
Please follow following URLs that give you more information.