The Hierarchy Tab shows the current structure of your scene. You can use it to navigate through the objects in your scene. You can right click on an object in the list to display a few options:
Zooms in on the selected object. This is especially useful if you can’t find a specific object in your scene.
Removes all effects from the selected model, including solid color, x-ray, and highlighting.
Resets selected model to its original position.