Each unit is known in Hebrew as a "sedrah" or "parashah." They are named for their first important Hebrew words or phrases (in early texts, most sedrahs had two-word titles, now one-word titles are the norm). The chief divisions in most Jewish Bibles reflects this system, which is consistent with the manner of their use in the synagogue service. The sedrahs have no necessary correlation to the chapter and verse numbers (which are not of Jewish origin), and a new sedrah may begin in the middle of a numbered chapter. For this reason, Sedrah names are not usually indicated in bibliographical references to the Torah.
In the ancient Palestinian rite, the Torah was not read each year, but over a period of about three and a half years, producing a division into some 150 smaller units. Although there were several Jewish communities, especially in Egypt and southern Italy, that maintained this practice well into the middle ages, the Babylonian annual cycle was eventually adopted throughout.
Although there is no formal acknowledgement of the Palestinian Sedrah divisions in most Jewish printed Bibles, those divisions underlie some of the Masoretic divisions into paragraphs, as well as the structure of most classical midrashic works from the Talmud era.