The Tcl commands in the Vivado Design Suite provide direct access to the object models for netlist, devices, and projects. These are Vivado first-class objects, which means they are more than just a string representation, and they can be operated on and queried. There are a few exceptions to this rule, but generally “things” can be queried as objects, and these objects have properties that can be queried and they have relationships that allow you to get to other objects.