So what is a "BootStrap"?
Bootstrap is a very popular, front-end library that focuses on design elements and UI styles for a standardized, easy to maintain theme. Orignally created as an "in-house" tool for Twitter, it was later released as on open source project. A few revisions and years later we are now at Bootstrap 4 which is almost in release state. Most well known for its mobile first approach and flexiable "grid" system for orginizing content, bootstrap can be found in many large, modern websites.