When you double-click on a field in your Data Source, the field is automatically added to a shelf on the Worksheet. Tableau decides where the field should be, based on data visualization best practices. 

Of course, there are limitations to what you can do with double-clicks. You won't be able to create a lot of different visualizations. You'll never go outside certain predefined scripts. Very soon, you'll feel limited. 

However, a double-click is always the most efficient way to build a map. A simple double-click on any Geographical Dimension and Tableau automatically puts the Latitude in Rows and the Longitude in Columns. 

The second way of letting Tableau do the work is to use Show Me, the menu that appears at the top-right of the toolbar.