The term Tawheed linguistically means oneness. Tawheed can only be established with negation and affirmation, which are the two pillars of the expression of Tawheed: “Laa ilaah illa Allaah (there is no deity but Allaah)”; negating "there is no deity" and affirming "but Allaah". In other words, Tawheed means negating anything that is worshipped apart from Allaah The Almighty and affirming that worship must be exclusive to Him alone. Altogether, this means that there is no true deity worthy of worship but Allaah The Almighty.

Technically speaking, it signifies worshipping Allaah The Almighty alone without associating any partner with Him.

There are three aspects of Tawheed that scholars deduced from their thorough study of Sharee‘ah texts:

1-      Tawheed Ar-Ruboobiyyah [Oneness of Lordship]. Scholars defined this as belief in the oneness of the actions of Allaah The Almighty, meaning that we believe that Allaah The Almighty is the only Creator, Proprietor and Disposer of all affairs. Allaah The Almighty Says (what means): {Allaah is the Creator of all things, and He is, over all things, Disposer of affairs.} [Quran 39:62]

2-      Tawheed Al-Uloohiyyah [Oneness of worship]. It means that people must dedicate all their acts of worship to Allaah The Almighty alone without associating any partner with Him. Allaah The Almighty Says (what means): {So whoever would hope for the meeting with his Lord - let him do righteous work and not associate in the worship of his Lord anyone.} [Quran 18:110]

3-      Tawheed Al-Asmaa' wa's-Sifaat [Oneness of His names and attributes]. It refers to describing Allaah The Almighty with the names and attributes that He described Himself with or His Messenger described Him with, without distorting their wordings or meanings, nor denying them, nor asking how they are, nor drawing any resemblance between Allaah and any of His creation, nor stripping their real Sharee‘ah-defined interpretations of their meanings; all are in accordance with the saying of Allaah The Almighty (which means): {There is nothing like unto Him, and He is the Hearing, the Seeing.} [Quran 42:11]

You may review the details of each kind in the books of Tawheed. This is the creed that Allaah The Almighty sent His messengers with to bring people out of darkness and into light, and out of worshipping people to worshipping the Lord of mankind, Allaah The Almighty.

Allaah The Almighty Says (what means): {And We sent not before you any Messenger except that We revealed to him that, "There is no deity except Me, so worship Me."} [Quran 21:25]  

Allaah Knows best.