Essentially all agree that pesukei dezimra, the Shema Yisrael and its blessings, and the Amidah are major sections.
[2] On certain days, there are additional prayers and services added to shacharit, including Mussaf and a Torah reading.
The sages of the Great Assembly may have formulated blessings and prayers that later became part of Shacharit,[4] however the siddur, or prayerbook as we know it, was not fully formed until around the 7th century CE.
During or before Shacharit, those Jews who wear tallit or tefillin put them on, in each case accompanied by blessings.
According to Jewish law, the earliest time to recite the morning service is when there is enough natural light "one can see a familiar acquaintance six feet away."