A more thorough explanation:

A manuscript is a written work that an author has created but has not yet been published. It can be a handwritten or typed document that is intended for publication.

• A novelist writes a book and submits the manuscript to a publisher for consideration.
• A scientist writes a research paper and sends the manuscript to a journal for peer review.
• An artist creates a graphic novel and shares the manuscript with a literary agent.

These examples illustrate how a manuscript is a written work that an author hopes to have published. It is the author's original work and has not yet been edited or published by a third party.