Zakah al-Fitr is often referred to as Sadaqah al-Fitr. The word Fitr means the same as Iftar, breaking a fast and it comes from the same root word as Futur which means breakfast. Thus, Islamically, Zakah al-Fitr is the name given to charity which is distributed at the end of the fast of Ramadan.
Sadaqah al-Fitr is a duty which is Wajib (required) on every Muslim, whether male or female, minor or adult as long as he/she has the means to do so. The proof that this form of charity is compulsory can be found in the Sunnah whereby Ibn `Umar reported that the Prophet ﷺ made Zakah al-Fitr compulsory on every slave, freeman, male, female, young and old among the Muslims; one Sa` of dried dates or one Sa` of barley.  The head of the household may pay the required amount for the other members. Abu Sa’id al-Khudri said, “On behalf of our young and old, free men and slaves, we used to take out during Allah’s Messenger’s (peace be upon him) lifetime one Sa` of grain, cheese or raisins”. 
The main purpose of Zakah al-Fitr is to provide those who fasted with the means of making up for their errors during the month of fasting. Zakah al-Fitr also provides the poor with a means with which they can celebrate the festival of breaking the fast (`Eid al-Fitr) along with the rest of the Muslims. Ibn Abbas reported, “The Prophet (peace be upon him) made Zakah al-Fitr compulsory so that those who fasted may be purified of their idle deeds and shameful talk (committed during Ramadan) and so that the poor may be fed. Whoever gives it before the Salat al-Eid will have it accepted as Zakah while he who gives it after the Salah has given (ordinary) Sadaqah.”  Hence, the goal of Sadaqah al-Fitr is the spiritual development of the Believers. By making them give up some of their wealth, the believers are taught the higher moral characteristics of generosity, compassion (sympathy for the unfortunate), gratitude to Allah and the righteousness. But, since Islam does not neglect man’s material need, part of the goal of Zakah al-Fitr is the economic well-being of the poorer members of society.
 Collected by Bukhari – Arabic/English, vol. 2, p. 339, no. 579
 Collected by Muslim – English transl. vol. 2, p. 469, no. 2155
 Collected by Abu Dawud – Eng. transl. vol. 2, p. 421, no. 1605 – rated Sahih by Shaikh Naser Al-Albani
 article of Dr. Bilal Philips in Zakat al-Fitr