React

React is a library for web and native user interfaces. Developers build an interface out of components, such as a button, a product card or a booking form, and combine them into full pages and apps. React components are JavaScript functions that return markup, so conditions, lists and data handling use ordinary programming logic.

React focuses on the interface. It does not include routing, data loading or a server on its own. Frameworks such as Next.js add those pieces for websites, and React Native brings the same component model to iOS and Android apps.

Why teams use React

• Reusable components keep a large interface consistent
• Interactive features such as filters, calculators and dashboards update without page reloads
• The same skills apply to web apps and React Native mobile apps
• A large ecosystem of libraries for forms, charts, maps and accessibility

Where React shows up in client work

React powers the interactive parts of modern websites: product configurators, quote calculators, appointment pickers, search filters and member dashboards. In a Next.js site, React components render on the server for speed and search visibility, and only the interactive parts run in the browser.

React also underpins mobile development with React Native and Expo. A business with a web portal and a mobile app can share design patterns and some logic between the two, which can reduce the work of keeping both in step.

Accessibility is a design decision in React, not an automatic feature. Custom components such as menus, modals and date pickers need correct labels, focus handling and keyboard support. Using semantic HTML inside components and testing with a keyboard and a screen reader catches most problems before launch.