Major shirk
Directing any worship to other than Allah — calling on saints, the dead, sacrificing to anyone but Allah, believing someone shares Allah's authority. Exits a person from Islam.
Minor shirk
Showing off in worship (riyā'), swearing by other than Allah, saying 'whatever Allah wills and you will' instead of 'whatever Allah wills, then you will'. Doesn't exit Islam but is dangerous.
Hidden shirk
Subtle attachment of the heart to other than Allah — the Prophet ﷺ called this 'more hidden than the crawling of an ant on a black stone in the dark.'
Today's Action
Examine your heart honestly — what attachments compete with Allah for first place?
Go deeper