Books increasingly don’t have covers. Most still do, but a growing percentage of published books appear on the screens of Kindles and tablets rather than bound paper, and this is even more true for other forms of print media, as articles, essays, stories, and personal memos splinter into browser tabs, tweets, threads, emails, and direct messages. Meanwhile, a larger subset of verbal communication has transformed into video, which only recently became as ubiquitously accessible as any reading material ever was. We still spend plenty of time reading—probably more time than ever, if in smaller increments—but the digital works we read on screens don’t have covers, those physical surfaces that visually mediate between content in its pure form and the surrounding world in which that content exists. Screens, and the devices of which they’re part, aren’t just a different kind of cover but an entirely distinct avenue of external approach, trading the cover’s individuality for a standardizing consistency that unifies everything displayed.

The declining importance of covers generalizes beyond print as all information migrates to the digital milieu. Music and movies both live comfortably on devices now, accessed via streaming platforms like Spotify and Netflix, or apps that play the files you still actually own yourself. Gone for most are the days of impressing friends at home with a monumental record collection shelved upon furniture designed for the purpose. While album covers still survive symbolically as visual, on-screen companions to digital listening (the apps might as well display something, after all), those covers have moved from the center of the experience to its periphery and are unlikely to reverse that trajectory. Like the envelope icon that still represents email, album covers are stylized, decontextualized reminders of what the technology you’re currently using has killed.

Covers haven’t stopped being useful, though. The folk warning against judging a book by its cover implies superficiality and even deception, qualities that companies hawking Kindles and other post-cover technologies would surely cite as support for their disruption. Rather than enticing us via a cover’s imagery, those disruptors might argue, digital platforms let us engage more directly and authentically with texts themselves. The supposed purity of the post-cover regime, however, is an illusion: While the ways that covers fool us are obvious by now, platforms’ algorithmic mediation represent a newer, more subtle (and less transparent) kind of deception, feeding us the unadorned content itself but concealing its own biases and affordances.

The notion that covers are separate from the content they contain is also a fallacy. For centuries the cover has functioned as the gateway to an artistic work, priming us to receive what’s within. In the Middle Ages, before books had formal titles (or distinctive covers), that role was fulfilled by the text’s incipit—”the first few words of the text, employed as an identifying label,” a similar gateway into the work itself. Titles and covers emerged later for the same reason, giving books context and connecting them to the surrounding environment while not quite being part of the work itself.

Given the cover’s pre-digital importance, it’s strange that covers lie almost entirely beyond the original artist’s scope of influence or responsibility. Sanford Kwinter writes that “a book’s cover (or to be precise, its jacket) belonged traditionally not to the book itself but rather to the retail or public environment in which a book is deployed and displayed, in which it claims its place among other books, and in relation to the public eye and mind of the citizen-reader. The cover was therefore conceived as a material part of the extended urban infrastructure within which it was intended to operate, was devised to serve as a communicative but also commutative and conductive surface.” Far more than a container or shell for content, the cover is an interface between that content and human society, the intermediate layer that positions information in the world.

Book covers, Kwinter writes, are infrastructure; thinking of them this way improves our understanding of what infrastructure actually is. Books, albums, and films are closed systems—complete works of art—that still, necessarily, have a relationship with the world that is external to them. Infrastructure is the physical and informational connective tissue that links and organizes a complex system—an institution, city, nation, or civilization. One early 19th-century definition of infrastructure was “the installations that form the basis for any operation or system.” The word’s meaning remains similarly broad today.

Defined another way, infrastructure provides context, establishing a relationship between one thing and other things. Infrastructure creates adjacency where it wouldn’t otherwise exist, frequently in the form of a physical connection. The massive Denver International Airport, opened in 1995, put an otherwise isolated, mid-sized city at the doorstep of the world, an exemplary case of infrastructural adjacency production. Urban street systems are the principal surfaces that link houses, stores, workplaces, and the traffic between them, thus defining neighborhoods and cities as coherent entities. Airports and roads, however, are only the most tangible examples of infrastructure. The internet and everything it comprises is also infrastructure at global scale, as are organizational schemas like geographic coordinates or the Dewey Decimal System. And again, covers are infrastructure. Our ability to find a printed book or vinyl record in physical space, as well as the very existence of spaces dedicated to perusing those media, depend upon those covers, as surely as our ability to explore a city depends on roads.

A physical book cover is like hailing a taxi by waving your hand in the air: an analog protocol for engaging with a physical object in a specific way. Digital protocols have emerged more recently as superior alternatives by many measures: Spotify holds far more music than any personal record collection ever did, and makes that library easier to browse. Uber similarly improves upon the need for mutual eye contact between taxi driver and passenger, expanding the range of possible matches by orders of magnitude and elevating those matches’ quality. Such digital protocols are also infrastructure—the more refined, rationalized, and totalizing kind we call platforms. Because platforms accomplish their specific goals so effectively—efficiency, legibility, and breadth of selection—they tend to rapidly replace their analog predecessors once they appear.

What platforms gain in efficacy, though, they lose in context. Or rather, platforms strip away the familiar sources of context and replace them with their own internal context (in tech lingo, those processes are called unbundling and bundling). Context is a valuable side effect of adjacency. Because we’re bad at articulating it as an explicit objective, we’re correspondingly bad at preserving it, and the transformations of the past few digital decades have demonstrated this as much as anything. We’ve lost a lot of context without fully noticing it, and into that void has flowed the new context that platforms provide—uncanny, unfamiliar, perhaps no worse than what it replaced, but requiring further examination. One certainty about the transition, as indicated by phrases like “watching Netflix” or “listening to Spotify,” is that platforms, as media, denature their content to some degree and assimilate its identity into their own. As individual works and artists become correspondingly less significant in their new environments, we should assess what that identity was worth.