When you select a node under the Elements tab, Chrome DevTools adds `== $0` right after the node.
In give us a hint that we can use the `$0` expression to access the selected node.
You can invoke any DOM APIs from `$0`.
The DevTools remembers the last five selected nodes. In addition to `$0`, we can use `$1`, `$2`, `$3` and `$4` to access the last selected nodes.
You also can right-click the node, and choose Store as global variable from the context menu. DevTools creates a variable, `temp1` for example, to represent the selected node.
Now you can use `temp1` to manage the node in the same way as `$0`.