When we are finished writing a book, while everything is hot and fresh in our mind there are some VITAL things we need to prepare that will be used in every step of getting the book represented, getting it published, and later in sales and promotion . The first is called a concept sentence, promo sentence or logline. It is a single SHORT sentence that tells the main concept of the book written in a very compelling manner.
The second is known as an elevator pitch or cover copy. It is a slightly larger version of the logline, 2-3 sentences that are used to pitch the book to an agent or editor if we find ourselves with a very brief opportunity to do so. Later it is used as cover copy and still later in advertising and promotion. These first two items are commonly used in our cover letter as well.
The third thing is a short synopsis or story summary. This is a slightly larger version of the first two, ideally a half page single spaced. It is used to produce a one page sell sheet, along with a logline as an attention getter on the page and with a very short WRITING RELATED bio. This will go in the proposal and the primary use of a sell sheet or one sheet is to provide an editor taking a project to committee to try and get it accepted with a single page to use or possibly to hand out that can be used to sell the project.
An agent, editor or publicist can write these for the book but ideally the best person to write them is the person that created the work from scratch, the one who lived with it from the ground up. A person trying to create them based on a brief read or two will surely not come up with as strong of an effort as the author.
Finally we have the synopsis itself. Most commonly desired is a 2-3 page single spaced synopsis that gives the main points of the story including the ending or plot resolution. This is not a chapter by chapter synopsis which may be required by a few editors but is more common on a nonfiction work than a fiction. Editors reading a proposal may read a synopsis first before reading the writing itself, may read it after reading sample writing to decide whether the story carries out in a manner that they would like to ready the full manuscript, or some may not use it at all but it should always be provided. Some submission guidelines require them to be longer and the submission guidelines should always be followed.
Even though these are presented in this order, they are often produced in a reverse order boiling the story down to get the synopsis, boiling the synopsis down to get the short synopsis or story summary, boiling it down to get the elevator pitch or cover copy and reducing it further to get the logline.
To give our work the best chance of success we as the originator of the work need to give these tools to the agent, editor or publicist to give them the best chance of advancing the work to its final conclusion. It is critical to provide these tools and to craft them to the best of our ability.