Before we dive into the definitions, I must offer a caveat: publishing is not a monolith. What an editorial assistant will be responsible for at Scholastic may differ wildly from the expectations at Graywolf. The smaller the press, the more hats one person will wear; the dividing line between acquisitions/line/executive editors may vanish entirely.
I’ve included what I take to be a fair description of each role in its narrowest form, with additional asterisks and complications included where necessary. However, if you’re interested in a particular role at a particular company, you should contact an employee from that company to get their opinion on the role’s expectations. The Dictionary is a launchpad for you to get started and feel comfortable. It is not Gospel. If it was, I would've named it Gospel.
With that out of the way…
The Manuscript - Before we enter the publishing house, we have to meet the people responsible for pulling the manuscript together and shopping it around the houses.
Author/writer - The person who writes the manuscript; or, maybe more accurately, the name on the cover of the book, but now we’re entering Foucauldian territory. Read What is an Author? by Michel Foucault if you want your brain to break.
Beta reader - The first set of eyes on a manuscript; usually non-professional, volunteer readers who offer their honest reaction for the writer to consider.
Developmental editor - The big-picture stage of editing, where editor and author work out questions about the story’s characters, plot, themes, etc.; in nonfiction publications, these questions may center on the breadth of the research. Editor and author will discuss the book’s tone, its place in its genre landscape, and how it can be a “better” read (“better” is perfectly vague; this can boil down to “more commercially successful”). Publishing houses are increasingly taking on manuscripts that arrive essentially ready to be published, so developmental editing is becoming the territory of volunteers, freelancers, and literary agencies.
Ghost writer - Someone who writes a book for someone, often without accreditation; think celebrity memoir. Although this is changing; some ghost writers are being credited under the headline author, as in “Headline & ghostwriter.” Whether these can be considered ghost writers, or are now to be considered co-authors, is up for debate.
Literary agent - Represents the author and their work to publishers; an increasing number of publishers, usually quite large, will only look at “agented” submissions.
Managerial Roles - A publishing house is a finely wrought machine; you must have someone winding the gears.
Editor-in-chief/executive editor - Both terms usually used to define the person at the top of the editorial chain. These terms can be used interchangeably, but usually editors-in-chief lead periodicals (newspapers, scholarly journals, etc.) while executive editors manage houses/imprints. You’ll hear that they’re “responsible for the editorial direction” of the house/periodical, a statement vague enough to clue you into the fact that there is a huge range of responsibilities that EICs/executive editors may have: they may set the style sheet, make hiring decisions, have the final say on acquisitions, work on budgets, directly or indirectly manage the editorial team, negotiate contracts, etc.
Managing/senior editor - Reports to the EIC/executive editor; a similarly flexible role, although their name will be less synonymous with the publication as a whole.
Publisher - Often refers to a press or periodical (e.g., Penguin is a “publisher”) although some houses list individuals as “publishers” (e.g., Milkweed, Princeton UP, Ecco, etc.). I’ve found it difficult to find a unified description of this role, but broadly, it's the person who's in charge. At the very least, they're ultimately responsible for establishing the vision for the press and allocating resources. The editors-in-chief and executive editors report to them.
Acquisitions - Those responsible for choosing the projects that a publishing operation takes on or “acquires.”
Acquisitions Editor - Independently or in an “acquisitions team,” an acquisitions editor decides which submissions the publishing house will fairy-godmother from manuscript into book, which can boil down to “how commercially successful would your book be?” or “how closely does your book align with our mission/brand?” Lots of number crunching involved either way.
Reader/Intern - Not interchangeable terms, but if I didn’t reference that classic image of the intern poring over the slush pile, I would be failing my duty as a student of publishing. Readers ultimately advise a publisher on the publishability of a submission, writing up reader’s reports with recommendations to the author as well as a final publishing decision (usually “publish with few edits/authorial discretion/as is,” “publish with substantive edits,” “revise and resubmit,” “reject,” although these terms can vary). The managerial team will compile these reports and make the final decision. Sometimes these reports are passed along to the author.
On the slush pile... The "slush pile," or backlog of unsolicited submissions, doesn't really exist at most major publishers. Many publishers only take "agented" submissions.
Editorial - Usually, the editorial path starts at developmental, moves to line edits, then copy edits, and then proofreading. These stages are often blurred or even entirely collapsed, but in the interest of clarity, I’ll describe them in their discrete forms.
Copy editor - A copy editor checks for grammar, spelling, punctuation, and internal consistency and may fact-check their author. Copy and line editors are collapsed into each other more frequently than other editorial roles (in my admittedly limited experience).
Developmental editor - The big-picture stage of editing, where editor and author work out questions about the story’s characters, plot, themes, etc.; in nonfiction publications, these questions may center on the breadth of the research. Editor and author will discuss the book’s tone, its place in its genre landscape, and how it can be a “better” read (“better” is perfectly vague; this can boil down to “more commercially successful”). Publishing houses are increasingly taking on manuscripts that arrive essentially ready to be published, so developmental editing is becoming the territory of volunteers, freelancers, and literary agencies.
Editor - A general term for someone who improves text or works in publishing. Its Latin root means "to produce." Editors usually have a supervisory role in addition to just working with the author and may organize multiple teams to ensure everything comes together properly. Freelance editors will also wear multiple hats, as they have to advertise, manage, and do all the accounting for their business.
What does a book editor do? | YouTube - from an industry perspective
What Does A Book Editor Actually Do? | YouTube - from a freelance perspective
Editor-at-large - Surprise! Usually not an editor in the traditional sense. Editors-at-large are instead essentially beat reporters—writers who specialize in an area like “science reporting” or “Foucauldian fountain designs.”
Editorial assistant - A rung above interns, editorial assistants are usually employees on the first step of their publishing journey. They fill in the gaps for the editorial team and perform a range of functions, including administrative tasks, permissions requests, answering authors, determining the publishability of a manuscript (see “reader/intern” above), etc.
Editor-in-chief/executive editor - Both terms usually used to define the person at the top of the editorial chain. These terms can be used interchangeably, but usually editors-in-chief lead periodicals (newspapers, scholarly journals, etc.) while executive editors manage houses/imprints. You’ll hear that they’re “responsible for the editorial direction” of the house/periodical, a statement vague enough to clue you into the fact that there is a huge range of responsibilities that EICs/executive editors may have: they may set the style sheet, make hiring decisions, have the final acquisitions say, work on budgets, directly or indirectly manage the editorial team, negotiate contracts, etc.
Line editor - Specializes in improving an author’s language for style and clarity. Copy and line editors are collapsed into each other more frequently than other editorial roles (in my admittedly limited experience).
Managing/senior editor - Reports to the EIC/executive editor; a similarly flexible role, although their name will be less synonymous with the publication as a whole.
Proofreader - After the manuscript is typesetted, designed, and ready for print (i.e., put through InDesign), it is now considered a collection of “proofs.” Proofreaders comb over these proofs for errors. This can be painstaking work, especially in an era where most editors’ eyes have deteriorated due to an overreliance on spell/grammar check. At this stage, no stylistic adjustments should be made, and very few errors should be found (but inevitably some will be unearthed).
Design & Production - Because you can’t put a Word doc on a bookshelf. (Although an E-Reader can, apparently, read a Word doc.)
Compiler - Someone who gathers the work of others into a single volume, like an anthology or contributed volume (although here they're usually called the "editor" of the volume)
Illustrator - The person who does the interior illustrations for a book or works on the cover art.
Indexer - The person who creates a book's index, that list of key terms in the back of the book.
Production manager/production editor - The person who shepherds the book from .docx to the file to be sent off to printers. Production editors are essentially project managers and form the connective glue between author, house, and freelancers. They oversee editorial and logistical aspects of publishing.
Typesetter - The person who arranges the text on the page, usually through InDesign.
Marketing & Publicity - Now that the book is on its way to completion, the house must spread word of its masterpiece ready to fly off the shelves.
Marketing Manager - Oversees the marketing process for books, including social media, ad campaigns, author talks, and so on.
Publicist - Advertises the book by working closely with the author to arrange book tours, interviews, or personal essays.
Social Media Coordinator - Falls under the general marketing team. Runs a press’s social media page, posting about upcoming releases, book fairs and editorial events, new hires, and so on.
Legal
Contract assistant/manager/executive - The "contract" is a document between author and publishing house that grants the house the legal rights to publish the author's work, usually in exchange for an "advance" (a chunk of money for the author and their agent, which will be counted against royalties) and "royalties" (an amount of money sent to the author for each book sold). Those working on the contract will create, edit, and negotiate the contract with the author.
Subsidiary rights agent - Negotiating all the rights relating to producing "subsidiary" or secondary products, separate from the primary product of the book itself, subsidiary rights agents negotiate with the author on merchandising, movie deals, translation, and audio rights.
Distributors
Bookseller/Retailer - Says it in the name: the people who sell the book to adoring readers; think Barnes and Noble, abebooks.com, or your local bookstore. Some publishers forge close relationships with certain booksellers (like Milkweed; check out their website for their “ecosystem” philosophy), but not all by any means.
Wholesaler - Book depots, essentially; buy books in bulk, store em, and sell to retailers.