HTML, or HyperText Markup Language, is the standard markup language for creating web pages. It provides the basic structure of the site, enhanced by CSS and JavaScript. HTML uses elements to describe content, making it essential for web development.

CSS, or Cascading Style Sheets, is used to control the presentation of HTML documents. By enabling layout, colors, fonts, and responsiveness, CSS helps developers create visually pleasing, adaptable web experiences.

Bootstrap is a responsive front-end framework by Twitter. It offers pre-designed components like buttons and grids, speeding up the development of mobile-first, visually appealing websites.