1. Compilation Process: One key difference between Angular CLI and CSS Blocks is the compilation process. Angular CLI compiles TypeScript code into JavaScript during build time, whereas CSS Blocks compile CSS and generate optimized output during build time as well.
2. Framework vs. Preprocessor: Angular CLI is a framework for building single-page web applications using TypeScript, whereas CSS Blocks is a CSS-in-JS tool that allows developers to write modular and scoped CSS styles without using preprocessors like Sass or Less.
3. JavaScript vs CSS: Angular CLI primarily focuses on JavaScript development, providing a comprehensive toolset for building robust applications, while CSS Blocks focuses on enhancing the CSS development experience by allowing for maintainable and reusable styles with performance optimizations.
4. Template Compilation: Angular CLI offers template compilation to convert HTML templates into highly optimized JavaScript code for performance, while CSS Blocks optimize the styles at build time to reduce the final CSS payload and improve loading times.
5. Component-based Development: Angular CLI promotes the use of components for structuring UI elements and logic, facilitating the development of scalable applications, while CSS Blocks enables component-based styling to create encapsulated styles that can be easily managed within individual components.
6. Dependency Management: Angular CLI manages dependencies for JavaScript libraries and tools required for building Angular applications, while CSS Blocks handles CSS dependencies and optimizations to ensure that styles are delivered efficiently.

In Summary, Angular CLI is a comprehensive framework for building single-page web applications with TypeScript, while CSS Blocks focuses on optimizing CSS styling and offering a modular and scoped approach to writing styles.