Webpack is a popular open-source module bundler for JavaScript applications that bundles and optimizes the code and its dependencies for production-ready deployment. It can also be used to transform other types of assets such as CSS, images, and fonts.

SCSS is a preprocessor scripting language that extends the capabilities of CSS by adding features such as variables, nesting, and mixins. It allows developers to write more efficient and maintainable CSS code, and helps to streamline the development process by reducing repetition and increasing reusability.