Interested to know about the API, Please give me some material or videos. for basic understanding.
What are you trying to do? There a couple of different API's depending on what you're trying to achieve.
https://onlinehelp.tableau.com/current/api/rest_api/en-us/help.htm - Manage and change Tableau Server resources
Become a Viz Whiz on the Forums!
Support the Community and master Tableau.
Retrieving data ...