One of Purim’s primary themes is Jewish unity. Haman tried to kill us all, we were all in danger together, so we celebrate together too. Hence, on Purim day we place special emphasis on caring for the less fortunate.
In order to best do this there are two mitzvos associated with giving on Purim. We give money (matanos l’evyonim) and food (mishalach manos) to at least two needy people during the daylight hours of Purim, March 21. At Chabad at Oberlin we collect funds to be distributed to families in need here in Lorain County on Purim day.
On Purim, we give a donation to whoever asks; we don’t verify his or her bank balance first.
As with the other mitzvahs of Purim, even small children should fulfill this mitzvah.