Erase allows for removing a cuboid selection, or 128 connected blocks of the same type.

Creating Selections

To create a selection, start by using left-click to select your first corner and then right-click to select the second. You can use middle-click to select faces instead of the corners. This makes it much easier to select blocks that don't already have edges.

With a selection, you're still able to expand the selection with middle-click. Using left or right-click also works to set a corner again.

Confirming Selections

After you're happy with your selection, use the del or backspace key on your keyboard to remove the selected area.

If you're not happy with the result, use Ctrl + Z to undo the deletion. If you can't make up your mind, you can use Ctrl + Y to redo your undo.

Erase Connected

To remove the nearest 128 blocks of the same type, use right-click while facing at the block you'd like to remove. The use of Ctrl + Z and Ctrl + Y still applies.

Below is a demonstration of both methods.