This book is based on React.js learning programming. React (also known
as React.js or ReactJS) is a free and open-source front-end JavaScript
library for building user interfaces based on UI components. It is
maintained by Meta (formerly Facebook) and a community of individual
developers and companies. React can be used as a base in the development
of single-page, mobile, or server-rendered applications with frameworks
like Next.js. However, React is only concerned with state management and
rendering that state to the DOM, so creating React applications usually
requires the use of additional libraries for routing, as well as certain
client-side functionality.