Zakat is one of the five pillars of Islam and also an act of worship. The meaning of zakat is "to purify" and so to purify our own wealth all Muslims are obliged to pay a portion of one's assets to help those in need. Zakat benefits the giver as well as the receiver.
In order to pay zakat, a Muslim must be adult, sane and possess the nisab (a minimum amount of wealth, shown above) for an entire year.
Assets to include in your zakat calculation are cash (on hand and in bank accounts), shares, pensions, gold, silver, business goods, crops and cattle.
You do not need to count personal items such as your home, furniture, cars, food, clothing, which are not used for business purposes.