What is the ruling on charity (sadaqah) and what is the ruling on zakat?

"Zakat" (obligatory charity) and "Sadaqa" (voluntary charity) are two terms between which there is an absolute general-particular relationship. Sadaqa is more general than Zakat; every Zakat is Sadaqa, but not every Sadaqa is Zakat. Zakat is a pillar of Islam, and it becomes obligatory on specific types of wealth, with particular amounts and conditions, and it is disbursed to designated recipients. As for Sadaqa, it refers to both the obligatory Zakat and the non-obligatory charity.