On a recent Tuesday afternoon in London, I asked a simple question to a full room: “How many people think of themselves as tech savvy, or digitally literate?”

Several hands shot up in response. I posed a second question: “How many people would say knowing how the Internet works has opened opportunity for them?”

Here, the reaction was almost unanimous — virtually all attendees raised their hands. The audience agreed that the Internet, when we know how to wield it, indisputably makes our lives better.

But the showing of hands suggested something deeper: It’s time we formally introduce web literacy into our education systems around the globe.

When the modern education system first emerged, we cast a trio of skills as its bedrock: the three Rs. Reading, writing and arithmetic have proven an indispensable foundation. But in today’s digital world — a world where a room full of strangers can so quickly agree on the web’s potential — one core skill is conspicuously absent from our education system: web literacy. The ability to explore, create and connect online isn’t an inherent part of curricula. That needs to change — web literacy deserves to be enshrined as the fourth R.

Timing is key. By 2025, almost five billion individuals will be online — a major increase from the 2.9 billion currently on the web. If equipped with web literacy education, these new users can use the Internet to unlock tremendous social and economic opportunities. The local shopkeeper can reach customers anywhere. A teacher can share and update lesson plans with students remotely. But if there’s limited understanding about how it all works, these new users will probably miss out.

Introducing web literacy at scale is an ambitious undertaking, but it starts with a modest task: defining what, precisely, web literacy is. It’s not a single skill, like being handy with HTML. Instead, web literacy is a collection of competencies, perhaps best divided into three categories: read, write and participate.

“Read” is how we explore the web. Web literate individuals understand what a browser is, and the difference between a URL and an IP address. They can evaluate web content, separating the useful and trustworthy from the drivel. And they have a grasp on security basics, like maintaining a sound password and avoiding online scams.

“Write” is how we build the web. Web literate students can transform a word into a hyperlink and attach media to an email. As they hone their abilities, they become more adept: at remixing other users’ content, writing code, applying a script framework.

“Participate” is how we connect on the web. This bucket ranges from the simple — engaging in a discussion on a chat forum, or, say, Medium — to the complex, like controlling what metadata is shared with certain services.