OS X El Capitan: select files or folders
Select a file or folder: Move the pointer over the item, then click it.
Select multiple files or folders: Hold down the Command key, then click the items.
Select multiple files or folders that are listed together: Click the first item you want to select, hold down the Shift key, then click the last item.
You can also click near the first item, hold down the mouse or trackpad button, then drag over all of the items.