The modifier stack ("stack" for short) contains the accumulated history of an object, including its creation parameters and the modifiers applied to it. If a modifier or object has sub-objects, such as Vertex and Edge with editable poly objects, you can access these directly within the stack.

Upper part of Modify panel, with modifier stack (white outline)
Adjust a selected object's creation parameters:
Click the object's name in the stack.
Primitive objects have a Parameters rollout. Other types of objects, such as editable poly, have a variety of rollouts.
Use the rollout controls to adjust the object settings.
Remove a modifier from a selected object:
Do one of the following:
(Remove Modifier From The Stack). This button is one of the tools below the modifier stack.Disable the effect of a modifier on a selected object:
When you first apply a modifier to an object, the modifier is enabled by default. When a modifier is enabled, its light-bulb icon in the stack is white, as depicted in the preceding illustration.
Do one of the following:
Click the
icon to the left of the modifier's name in the stack.
Clicking the icon toggles it between on and off.
Right-click the modifier in the stack display, and choose Off.
Alternatively, choose Off In Viewport or Off In Renderer to disable the modifier in one context but not the other.
Enable the effect of a modifier on a selected object:
Do one of the following:
Click the
icon to the left of the modifier's name in the stack.
Clicking the icon toggles it between on and off.
Right-click the modifier in the stack display, and choose On.
Resize the modifier stack display vertically:
Position the mouse cursor over the shaded bar below the tool buttons beneath the stack list.
The cursor changes to an up-and-down resize arrow, as it does at the horizontal edges of a resizable window.
Drag the bar vertically to change the size of the stack display in the Modify panel.
Use the modifier buttons:
Click
(Configure Modifier Sets), and choose Show Buttons.
This menu item is a toggle. It is either on or off. When you turn on Show Buttons, the current button set appears between the drop-down modifier list and the stack display.
Convert a selected modified object to an editable object:
Do one of the following:
Right-click the modifier stack, and choose Collapse All.
A dialog opens, warning you that the collapse operation cannot be undone, and gives you the option of performing a Hold before converting the object.

Right-click the object in a viewport, and choose Convert To > Convert to Editable Poly or other editable format from the quad menu.
Adjust a modifier's component such as its gizmo or center point:
Expand the modifier's hierarchy by clicking the
(plus-sign) icon.
Click the component to adjust, such as the Gizmo.
The component highlights to show it is active.
Adjust the component.
For example, you might use transforms to move a gizmo or a center point.
When done, you can hide the hierarchy display by clicking the
minus-sign icon. The modifier itself is highlighted again.
Access a sub-object level for a complex object:
Click the
(plus-sign) icon to display the object hierarchy.
Click the sub-object level to adjust.
The sub-object level highlights to show it is active.
Adjust sub-objects.
When you add a new sub-object type, the modifier stack updates to show the new sub-object levels. For example, when you add a point curve sub-object to a NURBS surface, the Point and Curve sub-object levels appear in the stack.
To exit the sub-object level, click the name of the top-level object.