Master Mac keyboard shortcuts
When you see a shortcut like hold all but the last key, then press that one. is the Command key, which is also labelled cmd. means the Option key, labelled alt or opt.
means the Control key, labelled ctrl, and shown as ^ in shortcuts in the menu bar. is the Shift key, which is typically just labelled shift. means the Delete key, which deletes to the left of the insertion point. Press to delete to the right.
is the Tab key, which shifts the focus between some controls in windows and web forms. Turn on Full Keyboard Access in System Preferences to jump between all controls.