A monorepo is a software development strategy where multiple projects or applications are stored within a single repository, allowing for code sharing and standardized practices across teams. This approach, particularly popular among web developers using JavaScript or TypeScript, offers advantages such as easier standardization, improved visibility, and simplified dependency management. However, it requires careful coordination of build pipelines and versioning, making it suitable for organizations with aligned technologies and skilled Git users. The text provides a detailed guide on setting up a TypeScript monorepo using npm workspaces, including configuring directory structures, managing dependencies, and utilizing build tools like Lerna, Nx, and Turborepo. The article emphasizes the importance of planning and the potential complexity of transitioning to a monorepo, suggesting that adopting this approach early in a project's lifecycle can maximize its benefits.