1. Workflow Automation vs Module Loading: Grunt is a task runner that automates various tasks in the development workflow such as minification, compilation, unit testing, etc., whereas RequireJS is a module loader that helps in managing dependencies and loading modules asynchronously in the browser.
2. Configuration vs Dependency Management: Grunt uses a configuration-based approach where tasks are defined in a configuration file, while RequireJS focuses on managing module dependencies through define() and require() functions.
3. Code Optimization vs Code Organization: Grunt can be used for code optimization tasks like minification and concatenation to improve performance, while RequireJS focuses on modularizing the codebase for better organization and maintainability.
4. Build Process vs Run-time Dependency Resolution: Grunt is commonly used in the build process to automate tasks before deployment, whereas RequireJS resolves dependencies at run-time based on the defined dependencies in the modules.
5. Task-based vs Function-based: Grunt organizes tasks that need to be executed in a predefined order, while RequireJS operates based on functions like define() to declare modules and require() to load modules dynamically.
6. Community and Ecosystem: Grunt has a wide range of plugins available for various tasks making it highly customizable, while RequireJS has a strong community support for managing module dependencies efficiently.

In Summary, Grunt is primarily used for workflow automation and code optimization, while RequireJS focuses on module loading and dependency management in web development.