What is the difference between a special resolution and a unanimous resolution?

Both are votes required for certain motions at general meetings (not at strata committee meetings).

A special resolution is where there must be at least 75% of owners in favour of the motion, based on unit entitlement.

A unanimous resolution is where everyone votes for the motion.

 

https://www.fairtrading.nsw.gov.au/housing-and-property/strata-and-community-living/strata-schemes/frequently-asked-questions-strata-schemes#MeetingProcedures