you'll be stacking boards (such as 2x4s) under the sink until it's at the exact height it needs to be. These boards will hold the sink in place while you glue it and while it is drying. As an alternative to stacking the board, you could place...
If you have chosen anunder-mount sink(which is the most common type of sink installation), at this point one of the installers will attach our rail or clip system for keeping that sink nice and snug up under the granite. Putting the Granite in Place, Setting the Seams, and Caulking Once...