# Mobile-first design

Concept · [Product](https://ecosystem.samcarlton.com/product)

Also called: mobile-first, mobile first, responsive design, responsive

Designing for small phone screens first, then expanding the design for larger screens.

**For example:** A local events site is designed mobile-first because most visitors arrive from a link on their phone.

## Connects to (3)

- [UX / UI](https://ecosystem.samcarlton.com/ux-ui): UI, the user interface, is what people see and tap on the screen.
- [Web app vs mobile app](https://ecosystem.samcarlton.com/web-app-mobile-app): A web app runs in a browser at a web address, on any device.
- [CSS](https://ecosystem.samcarlton.com/css): Cascading Style Sheets.

Map view: https://ecosystem.samcarlton.com/mobile-first-design