Zakaat is one of the five pillars of Islam. It has been mentioned, along with daily Prayers (Salaat), over seventy times in the Qur'an. Allah's word commanding "........and establish regular Salaat and give regular Zakaat......." are referred to in many parts of the Qur'an. From this we can conclude that after Salaat, Zakaat is the most important act in Islam.
Just as Salaat is the most important act of worship which has to be performed bodily, so is Zakaat the main act of worship which has to be performed monetarily. Those who fulfill this duty have been promised abundant reward in this world and hereafter. Whoever evades Zakaat has been sternly warned in the Qur'an and Hadith of the consequences.
Linguistically, Zakaat has two meanings: purification and growth. Technically, it means to purify one's possession of wealth by distributing a prescribed amount to the poor, the indigent, the slaves or captives, and the wayfarer.
There are many major benefits of giving Zakaat:
It reminds Muslims of the fact that whatever wealth they may possess is due to the blessings of Allah and as such it is to be spent according to the His commands.
Zakaat functions as a social security for all. Those who have enough money today pay for what they have. If they need money tomorrow they will get what is necessary to help them live decently.
Zakaat payer pays his dues to Allah as an act of worship, a token of submission and an acknowledgment of gratitude. The receiver of Zakaat receives it as a grant from Allah out of His bounty, a favor for which he is thankful to Allah.
Economically, Zakaat is the best check against hoarding. Those who do not invest their wealth but prefer to save or hoard it would see their wealth dwindling year after year at the rate of the payable Zakaat. This helps increase production and stimulates supply because it is a redistribution of income that enhances the demand by putting more real purchasing power in the hands of poor.
Zakaat is obligatory upon a person if :
He or she is an adult, sane, free and Muslim.
He/she must possess wealth in excess of specified minimum (Nisaab) excluding his or her personal needs (clothing, household furniture, utensils, cars etc. are termed article of personal needs).
It should be possessed for a complete lunar year.
It should be of productive nature from which one can derive profit or benefit such as merchandise for business, gold, silver, livestock etc