There are three categories of Tawhid:

1. Tawhid Ar-Rububiayyah (Lordship)
2. Tawhid Al-Uluhiyyah (Godhood)
3. Tawhid Al-Asma was-sifat (Names and Attributes)

Tawhid Ar-Rububiayyah:

The belief that Allah is the Creator, Ruler, and Sustainer or all things, and that He has partners in those matters.

Tawhid Al-Uluhiyyah:

The belief that Allah is the only One Who truly deserves to be worshiped and that He has no partner in that regard. And that is the meaning of Laa Ilaha Illalah, or "None has the right to be worshiped but Allah. " All acts of worship - such as prayer and fasting - must be performed sincerely for Allah alone; it is not permissible to direct even a portion of that worship to other that Him.

Tawhid Al-Asma was-sifat:

The belief that all that has been related in the Noble Quran or in the authentic Sunnah regarding Allah`s Names and Attributes must be established and affirmed for Allah alone, in a manner that is suitable to Him - How perfect He is - without changing their meaning or ignoring them completely or twisting the meaning or giving resemblance to any of the created things. Allah Almighty says:

Say: "He is Allah, (the) One, Allahus-Samad (Allah - the Self Sufficient Master, Whom all creatures need, He neither eats nor drinks), He begets not, nor was He begotten. And there is none coequal or comparable unto Him". And He Almighty says:

There is nothing like unto Him, and He is the All-Hearer, the All-Seer.

Some of the people of knowledge hold that there are two categories of Tawhid, simply because they have included the third category (Names and Attributes) under the first one (Rububiyah). There is no real difference in the two ways of classifying, because the goal of explaining Tawhid is achieved either way.

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There are three different kind of Shirk:

1. The Greater Shirk
2. The Lesser Shirk
3. The Hidden Shirk

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