Zakah is a religious obligation to give charity and allows you to purify your wealth. Wealth is on loan from God, so some should be used to help others. A sum of 2.5% is paid on income and savings to the mosque for distribution for community to causes.
Children do not have to pay zakah, but some guardians may pay on their behalf.
In countries with Shariah Law, it is illegal to not pay Zakah.
The Nisab threshold
The minimum amount a Muslim must have before being prescribed to pay Zakah
"Alms are for the poor and needy" Surah 2
"Know that whatever you acquire, a fifth of it is for Allah, for the Messenger, for the nearrelative and the orphans, the needy, and the wayfarer" Surah 8
Khums means a fifth in Arabic. This tax is paid on any profit earned by Shia muslims. Traditionally recipients of khums have been decicded by Shia leaders. For example: Descendants of Muhammed, Education projects and those in need.
The importance of giving Zakah includes:
To purify and cleanse your wealth - makes the remaining money clean
Share the blessing of wealth
Prevents greed
Money benefits both the giver and receiver (giver in afterlife)
If everyone gave zakah there would be no poverty - stewardship