SWC stands for Speedy Web Compiler, which is a super-fast JavaScript and TypeScript compiler designed to be a drop-in replacement for Babel. It uses a Rust-based parser and a JavaScript-based compiler to achieve faster compilation times than Babel. SWC is now a mature replacement for Babel, especially in the context of React projects. Vite, a fast and modern build tool for JavaScript applications, has an experimental option to use SWC as the JavaScript compiler, which can make builds faster and output smaller files. Vite also has a plugin called vite-plugin-react-swc that speeds up the Vite dev server with SWC. Using Vite and SWC together can significantly improve the development experience for React projects by reducing build times and output size.