A point within the element to treat as its "epicenter".

The Anchor partially specifies how an element is aligned within it's parent. Properties like Alignment and X, Y define a location in the parent to place the child, and Anchor specifies what child point is aligned there.

For example, <Panel X="50" Y="100" Anchor="25%,25%"> positions the middle of the top-left quarter (25%,25%) of the panel at point 50,100 in the parent.

Alignment implies a coordinate and anchor point, for example <Panel Alignment="BottomRight"> is that same as <Panel X="100%" Y="100%" Anchor="100%,100%">. You can use alignment and override the anchor, for examlpe <Panel Alignment="BottomRight" Anchor="50%,50%"> centers the panel at the bottom right point of the parent.