Tauheed (islamic Monotheism) has three aspects:
1. Oneness of the Lordship of Allah--"Tauheed ar-Rububiyya". To believe that,there is only one Lord for all the universe, its Creator, Organiser, Planner, Sustainer and Giver of Security etc., and that is ALLAH.
2. Oneness of the worship of ALLAH --"Tauheed al-Uluhiyya". To believe that none has the right to be worshiped {e.g. by praying, invoking, asking for help (from the unseen), swearing, slaughtering sacrifices, giving charity, Fasting, and Pilgrimage etc.,} but ALLAH.
3. Oneness of the name and qualities of ALLAH, "Tauheedul-Asma-was-sifaat". To believe that:
a. We must not name or qualify ALLAH except with what HE or His Messenger(peace be upon him) has named or qualified Him.
b. None deserved to be named or qualified with the definitive Names or attributes of ALLAH; e.g. AL-Karim (Most Generous).
c. We must confirm all of ALLAH''s Attributes which Allah has stated in his book (the Quran) or mentioned through his messenger Muhammad(peace be upon him), without changing them or ignoring them completely or twisting the meanings or giving resemblanceto any of the created things. {e.g. Allah is presemt over his throne,as mentioned in the Quran Ch.20:V5
These three aspects of Tauheed are included in the meaning of "LA ILAAHA ILLA ALLAH'' (None has the right to be worshiped but ALLAH).