What is a document that summarizes a project, its objectives, and how they will be achieved?

The document that best summarizes a project, its objectives, and the means to achieve them is the project plan. A project plan details the scope of the project, the timeline, resources needed, and the tasks that will be accomplished. It serves as a roadmap for how the project will be executed and managed, outlining the steps necessary to meet specific goals.

The project brief is generally a shorter document that offers a high-level overview but may not include the in-depth details found in a project plan. The project charter serves a different purpose; it formally authorizes the project and outlines its objectives, but does not typically contain the detailed steps on how to achieve those objectives. A project report is typically created after project execution to present the results and outcomes rather than to direct the project's implementation.

Thus, the project plan is the most comprehensive and appropriate document for summarizing how a project will be carried out in terms of objectives and achievement methods.