the first part of the declaration of independence was the preamable. what was the purpose of this part?

The purpose of the Preamble of the Declaration of Independence is to articulate the philosophical foundation for the American colonies' decision to separate from British rule. It outlines the Enlightenment ideals of individual rights and the notion of government’s legitimacy as deriving from the consent of the governed. The Preamble explains the purpose of government, emphasizes the importance of equality and unalienable rights, and asserts that people have the right to alter or abolish a government that fails to protect those rights. Essentially, it sets the moral and political reasoning for the colonies' pursuit of independence.