Zakah - The third pillar if Islam. Called the 'poor due' or alms or obligatory charity.
This is an amount of wealth that those who possess the minimum amount of wealth (an-nisaab) according to Islamic Law are required to give once a year to those entitled to financial assistance according to the Qur'an and Sunnah. It is basically 2.5 % of the money one has saved for a one year period. There are specifics with regards to different types of wealth and the specific amount owed must be calculated accordingly.
A compulsory form of charity collected once per year by the Islamic state from each Muslim member who has surplus wealth over and above his/her basic need which has remained in his/her possession for at least one year, if that surplus wealth is more than a designated minimum.
A certain fixed proportion of the wealth and of the each and every kind of property liable to Zakah of a Muslim to be paid yearly for the benefit of the poor in the Muslim community. The payment is obligatory as it s one of the five pillars of Islam. Zakah is the major economic means of establishing social justice and leading the Muslim society to prosperity and security.