The internet’s global expansion is entering a new phase, and it looks decidedly unlike the last one.

Instead of typing searches and emails, a wave of newcomers—“the next billion,” the tech industry calls them—is avoiding text, using voice activation and communicating with images. They are a swath of the world’s less-educated, online for the first time thanks to low-end smartphones, cheap data plans and intuitive apps that let them navigate despite poor literacy.

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