Zakat is an islamic social development system, that people shall help people according to a specific roles and routines. in fact, taxe system historically comes from here. The different is that taxe system has been developpd by people, and Zakat by ou God throuth Chariaa of our Profet Mohamed (PBUH. To siplify thinks how it works : Whatever you own as an extra of your needs to specific level of kind of living valuable to 80g grams of gold, you pay the equivalant of 2.5% after 12 months to poor people.
There is a specific branch in Chariaa that study this, with , of course, a apecialist.
Regards.