Jazakallah
Jazāk Allāh or Jazāk Allāhu Khayran is an Arabic expression of gratitude, meaning "May God reward you goodness."
Although the common word for thanks in Arabic is shukran, Jazāk Allāh khayran is often used by Muslims, regardless of ethnicity.
The response to this phrase is wa ʾiyyāk, or wa ʾiyyākum for the plural, which means "and to you". A more formal reply is "wa ʾantum fajazākumu llāhu khayran" "And you too, may God reward you with goodness".