1. Grid System: Bootstrap and Materialize use a traditional grid system with a 12-column layout, while Semantic UI uses a semantic grid with defined classes for different screen sizes. This allows developers to easily create responsive layouts, but Semantic UI's semantic grid offers more flexibility in terms of customization and responsive design.

2. Design Philosophy: Bootstrap follows a more traditional and conservative design approach, focusing on simplicity, consistency, and compatibility. Materialize follows a modern and visually appealing design approach, incorporating vibrant colors, shadows, and material design principles. Semantic UI also follows a modern design approach but emphasizes ease of use and intuitive class names.

3. Component Selection: Bootstrap provides a wide range of ready-to-use components, including navigation bars, forms, buttons, and modals. Materialize offers a similar set of components but also includes additional components such as parallax effects and floating action buttons. Semantic UI has a comprehensive set of components with a focus on ease of use, including advanced filtering, sorting, and search capabilities.

4. Customization Options: Bootstrap provides a variety of customization options through Sass variables, allowing developers to easily modify colors, spacing, breakpoints, and more. Materialize offers a similar level of customization through Sass variables, but also provides a theming tool that allows developers to create custom themes. Semantic UI provides a theming tool called "Theming Express" that enables developers to easily customize the look and feel of their website.

5. Documentation and Community Support: Bootstrap has been around for a long time and has a large community, extensive documentation, and a wide range of online resources and tutorials. Materialize has a smaller community compared to Bootstrap but still offers good documentation and resources. Semantic UI has a smaller community and documentation compared to Bootstrap and Materialize, but it is known for its well-organized documentation and helpful examples.

6. JavaScript Integration: Bootstrap has a robust set of JavaScript plugins that can be easily integrated into a project for enhanced functionality, such as carousels, tooltips, and modals. Materialize also provides JavaScript components, but they are not as extensive as Bootstrap's. Semantic UI offers a limited number of JavaScript modules, focusing more on the CSS and component aspect.

In Summary, Bootstrap, Materialize, and Semantic UI are popular front-end frameworks that offer different design philosophies, customization options, and component selections. Bootstrap is a more traditional and conservative choice, Materialize focuses on modern design and visual appeal, and Semantic UI prioritizes ease of use and intuitive class names. Depending on specific project requirements and preferences, developers can choose the framework that aligns best with their needs.