The pope is only infallible speaking ex-cathedra on faith and morals......Cyrillic said:Filioque - whether the Holy Spirit proceeds from the Father or from the Father and the Son
Papal Infallibility - Catholics say the Pope is infallible when speaking ex cathedra, Orthodox deny this.
Papal Supremacy - Does the Pope have Universal Jurisdiction? Catholics say yes, Orthodox say no.
These are the big three. There are some more but they usually have less substance.