Conversations in the field of computers and writing can casually refer to genres, mediums, and platforms. Those involved (or who overhear) are expected to follow along without trouble. But the situation is different in undergraduate courses, where students often encounter our specific use of these terms for the first time — or at least the first time the distinctions really matter. Here I attempt to define, and differentiate among, the three concepts in a way that helps ease conversation and encourage investigation.
Genre, but not how they mean it in literature courses
The biggest source of confusion and frustration often comes from the word genre. In literature courses and most high-school classrooms, the term is used near-synonymously with category. It’s what structures English curricula in many places: short stories, novels, plays, etc. It’s what helps you browse through and select a movie you’re in the mood to watch: comedy, thriller, action/adventure, horror, sci-fi. And you use it to identify groups of music that suit (or offend) your taste: hip-hop, country, classical, jazz, metal, rock. In each of these cases — literature, movies, and music, we use the term genre to denote a broad category of creative product based on its form and style.
But in your writing courses, from first-year writing through senior-level rhetoric classes, instructors will use the term very differently. In composition circles specifically, the word genre means a typified response to a recurring rhetorical situation (see Devitt 1993 for more details). That means a particular set of circumstances necessitating communication (usually writing) happen so often and so regularly that the type of communication used becomes regular, familiar, and specific. The way we use this term in writing classes looks less at broad categories and more closely at the action taken by a specific type of document. What a genre does defines the genre and helps you identify and name it.
Example of a Genre
For example, every time a customer purchases something from a store, the customer needs documentation of what was purchased. This documentation needs to help in case of pricing disputes, product returns, and other customer-service-related issues. It needs to include what was purchased, what was paid and how it was paid, plus where and when the transaction took place. You already know I’m describing a receipt. You know this specifically because the genre is so regular that you’ve come to expect one after every transaction, so familiar that you followed along with a vague description, and so specific that you probably saw in your head exactly what a receipt looks like as I described it.
But the receipt you imagined doesn’t actually exist. It’s generic.
The receipt you imagined didn’t have a specific store’s name on it — you just knew where the store’s name belongs. It didn’t include actual product names or prices, but you imagined where the product names are listed and what the price list looks like. You certainly didn’t think of the cashier’s name or the store’s address or the credit-card number associated with the purchase, but now that I’ve mentioned those things, the image in your head has made space for them. Because you have a functional knowledge of what a generic receipt should look like. Any time you can imagine a generic such-and-such, you’re talking about a genre. Think about a generic wedding invitation, a generic report card, a generic high-school textbook, or a generic book of nursery rhymes. Each of those is used to meet the typical needs of a recurring rhetorical situation.
Mediums, used differently from media
Your phone stores a bunch of media on it. Your photos, music, and movies are what’s generally meant by the term media in that case. But technically, it should also include text notes because they can be saved, organized, searched, and retrieved just like pictures and songs. Our society just considers text as a baseline and the default means of communication, so media generally means anything fancier than words.
In order to discuss what a medium is, I’ll often refer to its plural form, which is usually media. But that might cause confusion given what I just said, so for clarity, the word mediums is often used to mean various forms, physical or digital, in which a message can be sent or stored. For instance, I can send a message as a text message, as a note written or typed on paper, as a verbal presentation, through morse code on a signal light. On my computer, I can save an essay as a text file, a .docx file, or a .pdf file. Each medium has its own distinct set of affordances and constraints to deal with, and while it might seem like a message could move easily among various mediums, it’s rarely so simple (see McLuhan 1967 for more details).
Separating Product from Tool
It’s important to note that the medium used is agnostic of the tool used to create it. For instance, with the essay I mentioned in the previous paragraph, I can use Microsoft Word to save a .docx file, but I can also create the same kind of file using Apple Pages, Google Docs, Apache OpenOffice Writer, or dozens of other apps. We call the file type a “Word document” but that doesn’t necessarily mean it was created in Microsoft Word.
Unlike genres, there’s nothing about a medium that suggests how it will be used. The medium defines only the physical or digital characteristics of how the message content is stored and conveyed. So when I suggested the generic examples of wedding invitations, report cards, textbooks, and receipts, you probably imagined each of them using the medium of paper — some on card stock, some on thermal paper, but all on paper. Each of those examples has been recreated in digital forms, but often those new forms are meant to look and act like the paper-based predecessor. (In composition, we call that remediation, which should make sense if you break down the word.)
Platforms, which are easy to confuse with apps
When you log into a system and work with its interface to manage content, you’re using a platform. Technically speaking, platforms offer services to apps and devices through a set of APIs. But more importantly, platforms control access to, and determine what can be done with, the content they maintain. This is most often done through a web interface, but it can also involve granting apps access to content in certain ways. Apps on your phone, tablet, and notebook often interface with platforms to let you work with material.
For instance, think of your favorite social-media platform. I’ll use Twitter as an example, but whichever one you use most often works the exact same way. Twitter, as a whole, isn’t just an app or just a webpage or just a tool. While it allows for all those things, Twitter itself is just the system those things all work on top of. When you sign in to Twitter, you see whatever you set your account to show you. When I log in, I see something very different. Yet we’re both using the same platform. We could even be looking at web pages with the same URL (twitter.com in this case), but the content we see there would be completely different. That’s because Twitter, the platform, determines what content you should see when you sign in and delivers the content it thinks is appropriate to you.
Platforms can present content in the user’s preferred language, or with the user’s favorite color scheme. More importantly, they determine which pieces of content each user sees. Any time you have a feed of content, it is fed to you by a platform using algorithms that determine what you should see, in what order, and with which ads.
How Platforms Work
Back to the example of Twitter, that one platform can be accessed in myriad ways. I can go to twitter.com, I can open the Twitter app on any of my devices, I can send a text to 40404, or — and this is important — I can use any one of a bunch of other apps not made by Twitter that let me log in to the Twitter platform and access my content. For that matter, many operating systems have Twitter support built-in. It’s possible, for instance, to take a photo on your phone and post it directly to Twitter without opening a dedicated app. That’s because your phone’s software has a built-in connection to the platform. In short, Twitter is this thing (a platform) that we can access however is best for us.
It’s helpful to understand what a platform is because platforms control how you see their content and what you can do with them. Their interfaces make certain actions easy (like creating an account and seeing which of your friends already has one) and make other actions hard to find (like close your account, which often requires several steps and confirmations). The terms they use for actions you can take shape your perception of how the service works. (Twitter used to have “favorites” with star icons but since changed the term to “likes” with heart icons. You only have so many favorite things, but you can like an infinite number of things. That wording change affects how often the feature is used.)
Examples of the concepts in practice
Now that I’ve reviewed the basic concepts behind the three terms, let’s look at how they work with a couple specific examples. I’ll start with a clarifying example that should help bring home the points I’ve been making above. It will help show how differentiating these concepts plays out in daily practice. Then I’ll provide a confounding example so you can check your understanding as we try to untangle a particularly thorny form of communication.
To clarify: Digital Photos
Let’s consider a photo taken with your phone. Specifically, a selfie you take to show friends you’ve arrived at a fun destination — a bar, restaurant, party, etc. That’s the genre: an “I was here” selfie. You know what those look like. All smiles, probably taken at an angle, and with something in the background making it unmistakeable where you are. You can probably imagine one of these photos in your mind right now. We’ve all seen them before.
Once you take the photo, it exists as a digital picture, which is the medium. To get a bit more specific/technical, it’s probably a .jpg or .heif image file. But for the sake of illustration, “digital photo” works well enough. You can open that photo in any number of devices or apps, and you can do pretty much whatever you want with it. The fact that you took it with your phone doesn’t really matter to any of those apps. (Though the file contains that information if the apps care to know. That’s due to what Manovich  calls transcoding.)
When you post that photo to your social account, you’re using that platform to share your photo with others. You might post your photo to Instagram, but because I’m old, I’ll probably post mine to Facebook. The same file — our digital photo — works on whichever platform we want. And all our social platforms are able to work with the common medium of digital photos.
To confound: Email
Because of its ubiquity, email seems always to be the answer to everything. And it causes no end of trouble when explaining concepts because it seems to obvious but rarely works as we expect.
First rule: Email is not a genre. You create genres with email.
Remember that a genre’s purpose defines it. You can think of a generic version of a genre. That’s not possible with email because there are too many options — email is used for too many purposes. I get weekly email updates from my school’s president, monthly emails from credit cards telling me my payments are due, and annual emails from platforms reminding me of their privacy policies. No two of those examples look alike — bills don’t look like privacy updates, for instance. But each example is its own genre because you can imagine what a billing-statement email looks like. And next time you get a privacy-policy update email, you’ll roll your eyes saying, “Another one?” Each of my examples is a genre. But email, as a whole, is way too broad to be a genre.
Second rule: Email is not a platform. You use platforms to access email.
To be clear: You don’t sign in to your email. You sign in to a platform that provides access to your email. For example, I use Gmail for a lot of my email. I think I have five separate Gmail accounts right now. But I also have one account with my hosting provider and two through Office 365. To access my email, I have to sign in to a platform that lets me access my account. But I can do that from a web page (like gmail.com or office365.com) or a dedicated app (like the Gmail app or Outlook) or use the built-in Mail app on my phone, tablet, and notebook. The software I use to access it doesn’t matter because the software provides access to the platform.
Third rule: Email is a medium. It’s the substance in which you create messages.
We use email as a medium for our messages. It’s a flexible and inescapable as paper. Email, like paper, works for millions of purposes. The medium doesn’t determine the genre…or the message. Each email message is like a digital photo, in a way. It doesn’t matter where it was created or what app made it; so many apps know how to work with it that things just sort of work smoothly together.
Understanding how different technologies work together can help you understand how your devices and your data are being used. And understanding distinctions among genres, mediums, and platforms can help you communicate more effectively and intentionally.