Smartphones existed before 2007 — they had keyboards, styluses and email. But when Apple unveiled the iPhone, it reframed what the device was: a full-screen, multi-touch computer that happened to make calls. No stylus, no plastic keys — just a slab of glass you touched directly.
Why it mattered
The iPhone, and the flood of Android phones that followed, moved computing off the desk and into the pocket of ordinary people worldwide. The 2008 launch of app stores turned the phone into a platform: a single device that could become a map, a camera, a bank, a game console or a television, just by installing software.
For a large share of humanity, the smartphone became the first and only computer they ever owned, and their primary door to the internet. It reshaped whole industries — photography, taxis, retail, media, social life — and made "mobile first" the default assumption for anyone building software, including the sites and apps you use today.