A project charter is a critical document that outlines the project's purpose, objectives, scope, stakeholders, and high-level requirements. It is essential because it provides a clear roadmap for the project team to follow and ensures that everyone is on the same page. The charter also helps stakeholders understand the project's value, risks, and benefits, making it easier to obtain buy-in and support. By setting clear goals and boundaries, the charter can help prevent scope creep and ensure that the project stays on track. Overall, a project charter is a vital tool for project success, as it establishes a solid foundation for the project's planning and execution.