What is the affirmament?

The "firmament" is a term historically used to describe the sky or heavens, particularly in ancient cosmologies and religious texts, such as The Bible. It often refers to a solid dome-like structure that separates the Earth from the celestial waters above. In a broader sense, the term can symbolize the universe or the expanse of space. Today, it is less commonly used in scientific contexts, which instead refer to the atmosphere or outer space.