Elements, wire segments, and wire corners (collectively called items) can be moved by placing the cursor over the item, pressing and holding the left mouse button, dragging the item to its new position, and finally releasing the mouse button. Notice that the pink bounding rectangle of the item will be shown while it is being dragged, and that the blue message bar will indicate when items cannot be placed in their currently shown place.
You can select multiple items and move them en-mass. First select the items you want to move. Then press the left mouse button anywhere in the gray area, drag the selected items to their new place, and then release the button. The gray selection rectangle will disappear while you are dragging, but the selected items will still be shown in pink.
If any item cannot be placed in the currently shown place, releasing the mouse button will result in the items returning to their original position.