Bootstrap

Bootstrap is a free and open-source CSS framework for building responsive and mobile-first websites and web applications. Bootstrap was developed and is maintained by Twitter, and it is one of the most popular CSS frameworks in the world.

Bootstrap includes a rich set of predefined CSS classes and JavaScript components, such as buttons, forms, and navigation bars, that can be easily and quickly used to build user interfaces and other web application features. Bootstrap is built on top of the CSS Flexbox layout model, which makes it easy to create flexible and responsive layouts that adapt to different screen sizes and devices.

To learn Bootstrap, you can start by reading the Bootstrap documentation and tutorials, and by practicing writing and experimenting with Bootstrap code. There are also many online courses, books, and other resources that can help you learn Bootstrap and become proficient in using Bootstrap for web design and development. Additionally, the Bootstrap community is active and supportive, and there are many online forums, blogs, and other resources where you can learn from and connect with other Bootstrap developers.