Bootstrap is a framework that has been developed by Twitter, to design websites consistently. The open source project is very well received today outside of Twitter as well.
Bootstrap Logo (Source: Logonoid.com)
Originally Bootstrap was developed as an internal tool for Twitter, to curtail the use of different libraries and the resulting inconsistencies. When it turned out that bootstrap could be used much more broadly, Twitter published the tool in August 2011 as an open source project. It is available through the hosting service GitHub and is being continually enhanced by freelance developers since its release.
This YouTube video explains in a tutorial in German what a Bootstrap is.
Bootstrap was originally made to create front end websites. Meanwhile, it is, however, also used to build the backend of websites and to create web applications. Bootstrap is often associated with the term “responsive design” because with this Twitter framework, user interfaces can be designed dynamically so that they always conform to the format and the display size of the device being used in each case, whether computer, netbook, tablet, or smartphone.
The Bootstrap framework provides a number of advantages:
Bootstrap makes it possible to reduce the loading time of websites, since only those components must be installed which are really needed. This can positively impact a website’s ranking, since page speed plays an important role. Moreover, Bootstrap simplifies the generation of clean code and improves the user experience on a website.