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 wealth all Muslims are obliged to pay a portion of their assets to help those in need. In order to pay Zakat, a Muslim must be adult, sane and possess the nisab (a minimum amount of wealth) for an entire year.
Assets you must include in your Zakat calculation are the following, cash (on hand and in bank accounts) gold, silver, pensions, shares, business goods, cattle and crops. However, you do not need to calculate personal items for example, your home, furniture, cars, vehicles, clothing, food, that are not used for the purpose of business.