In terms of sharee’ah or Islamic terminology, shirk means ascribing a partner or rival to Allaah in Lordship (ruboobiyyah), worship or in His names and attributes.
The scholars divided shirk into two types:
1 – Major shirk
This means ascribing to someone other than Allaah something that belongs only to Allaah, such as Lordship (ruboobiyyah), divinity (uloohiyyah) and the divine names and attributes (al-asma’ wa’l-sifaat).
This kind of shirk may sometimes be outward, such as the shirk of those who worship idols and graves, or the dead or absent. Or it may sometimes be hidden, such as those who put their trust in other gods besides Allaah, or the shirk and kufr of the hypocrites because they make an outward display of Islam and conceal their kufr and shirk.
Shirk may sometimes take the form of beliefs or words or actions:
The belief that there is someone else who must be obeyed absolutely besides Allaah. Or by loving a created being as they love Allaah.
Shirk may sometimes take the form of words:
The words such as those who make du’aa’ or pray to someone other than Allaah.
Shirk may sometimes take the form of actions:
Such as one who sacrifices, prays or prostrates to something other than Allaah.
2 – Minor shirk
This includes everything that may lead to major shirk, or which is described in the texts as being shirk, but does not reach the extent of being major shirk.
This is usually of two types:
1 – Being emotionally attached to some means which have no basis and for which Allaah has not given permission, such as believing in some objects that they offer protection or that they ward off the evil eye.
2 – Venerating some people or things in a way that does not go so far as ascribing lordship to them, such as swearing by something other than Allaah, or saying, “Were it not for Allaah and So and so,” etc.
What the Muslim must do is to avoid shirk in both its minor and major forms. The greatest sin is shirk and transgression against the unique rights of Allaah, which are to be worshipped and obeyed alone, with no partner or associate. Hence Allaah has decreed that the mushrikeen will abide forever in Hell and has told us that He will not forgive them, and He has forbidden Paradise to them.