Shema refers to a prayer, named Shema after its first word. It is traditionally said 3 times a day: in the morning and evening prayers, and before retiring at night. Shema may refer to the first verse (Deut. 6:4), the longer version which includes Deut. 6:5-9, 11:13-21 and Num. 15:37-41, or the even longer prayer said before bed.
Shema Yisrael (or Sh'ma Yisrael) (Hebrew: שְׁמַע יִשְׂרָאֵל; "Hear, [O] Israel") are the first two words of a section of the Torah, and are the title (sometimes shortened to simply "Shema") of a prayer that serves as a centerpiece of the morning and evening Jewish prayer services. The first verse encapsulates the monotheistic essence of Judaism: "Hear, O Israel: the LORD is our God, the LORD is one," found in Deuteronomy 6:4. Observant Jews consider the Shema to be the most important part of the prayer service in Judaism, and its twice-daily recitation as a mitzvah (religious commandment). It is traditional for Jews to say the Shema as their last words, and for parents to teach their children to say it before they go to sleep at night.