Under the kinds of shirk, As-Sanuusiy (895 AH) mentions:
“There are six types of shirk:
-Shirk of independence, which is to believe that there are two independent gods, like the shirk of the Majuus (the religion of ancient Persia.)
-Shirk of dividing, which is to compose a deity from several deities, like the shirk of the christians.
-Shirk of “making near,” which is to worship other than Aļļaah to (according to those who do it) get closer to Aļļaah’s acceptance, such as the shirk of the early Arabs of the Jaahiliyyah period.
-Shirk of immitation, which is to worship other than Aļļaah because others are doing it, like the later generations of Arabs in the Jaahiliyyah period.
-Shirk of causes, which is to believe that ordinary causes have effect in reality, like the shirk of the philosophers and naturalists, and those who follow them in this.
-Shirk of purpose, which is to do something (prescribed by Aļļaah) for the sake of other than Aļļaah (i.e. only for the purpose of being rewarded or praised by other than Aļļaah).
(Sħarĥu-l-Muqaddimaat, P. 46)”
In the above, As-Sanuusiyy focuses on the shirk of believing that someone other than Allaah has actual and real power to influence events, or of worship of other than Aļļaah for whatever reason. Just as it is shirk, however, to believe that someone has power like Aļļaah’s Power, it is shirk to believe that some creation has an attribute like one of Aļļaah’s attributes other than Power. Another example of shirk is disbelieving in the known judgments of Aļļaah (such as the obligation of the 5 daily prayers, or the prohibition of drinking wine) based on following someone’s opinion, like a priest or a monk. ˆIzzu-d-Diin ˆAbu-s-Salaam mentioned these in his “Maqaaşidu-ş-Şalaat. Arguably, they could be fit under As-Sanuusiyy’s mentioned types.
In the end it comes back to one underlying concept, which is to believe that Aļļaah has a like in some aspect. So those who believe that causes in normal life have actual influence on other events, are believing that Aļļaah has partners in His Power, while those who worship other than Him believe He has partners in godhood, and those who believe that Aļļaah is in a place believe He has partners in His existence, etc.