Switches to node-selection mode.

Switches to edge-selection mode.

Switches to face-selection mode.

Switches to element-selection-mode.

To add an item to the current selection, just shift$+$ click the item. When tags are enabled, a dot followed by the item's number will appear next to the item. To enable the tags, select the corresponding button on the toolbar. To remove an item from the current selection, ctrl$+$ click the node or element. You can (de-) select multiple items at the same time by dragging the mouse cursor while holding down the shift or ctrl key and the left mouse button. A colored rectangle will appear indicating what elements or nodes will be selected. Note that only visible elements or nodes that fall inside this rectangle will be selected. This means that only elements or nodes on the surface of the mesh can be selected.

When no other windows are open (such as e.g. Graph windows, etc.), pressing the ESC-key will clear the selection. You can also select the Edit/Clear Selection menu to clear the entire selection.

Also note that the Edit menu lists several options to manipulate the current selection, such as hiding, un-hiding, inverting, etc.