Short answers, pulled from the story.
The Coffin Texts are a collection of roughly 1,185 ancient Egyptian funerary spells that date to around 2100 BCE. They began appearing on coffins during the First Intermediate Period and continued into the Middle Kingdom. They are partially derived from the earlier Pyramid Texts but contain substantial new material aimed at ordinary Egyptians rather than royalty.
Any ordinary Egyptian who could afford a coffin had access to the Coffin Texts. This was a significant departure from the earlier Pyramid Texts, which were reserved for the pharaoh alone. The Coffin Texts effectively ended the pharaoh's exclusive rights to an afterlife.
The Duat is the subterranean realm of the dead described in the Coffin Texts, ruled by the deity Osiris. The texts portray it as filled with threatening beings, traps, and snares. The spells were intended to help the deceased navigate these dangers and avoid what the texts called "dying a second death."
The Book of Two Ways is a collection of spells and graphical maps of the underworld found on coffins from the necropolis of el-Bersheh. It is considered the first known ancient Egyptian map of the underworld. It forms part of the broader Coffin Texts tradition and served as a precursor to the New Kingdom books of the underworld and the Book of the Dead.
Many spells from the Coffin Texts were later copied into the Book of the Dead, including shortened versions created to fit limited writing surfaces. The Coffin Texts also introduced the concept of judgment by Osiris using a balance, which became the central moment of judgment in the Book of the Dead.
Beyond the wooden coffins that give the collection its name, the Coffin Texts were inscribed on tomb walls, stelae, canopic chests, papyri, and mummy masks. Because some of these surfaces offered limited space, scribes often produced abbreviated versions of the spells.