I have come across this opinion that zakaat is on money also other than gold/silver coins
like in the following lecture by Syed Jawad Naqvi as per 12 minutes on
He mentions zakaat was later introduced on horses and rice also after the Prophets (صلى الله عليه وآله وسلم) time as that was what the people started possessing.
He was also mentioning how is it that a rich factory owner don’t have to pay zakaat but a poor farmer as to pay zakaat on his few animals.
while studying about zakaat, it seems that main guide is that the zakaat is on gold or silver coins that are used as currency but now there are views that it's on note currency also n some say it's precautionary caution to give on those as well.
Really confused about the matter of zakaat now.
Thoughts?