Bootstrap is a powerful HTML, CSS, and JavaScript Framework, a library of reusable pieces of code. It is an open-source and free front end toolkit to help you create responsive and mobile-first websites.
It was released in 2011 by Twitter as an internal development tool, later it was laid out in open access on GitHub. It has been an essential tool for web developers over the years because it is flexible and easy to work with, and has maintained a high quality standard over the years with wide browser compatibility.
In addition to being easy to use it’s also quick to learn. A basic knowledge of HTML and CSS is enough to build responsive web pages and customize them to your needs.
Bootstrat can be easily downloaded from the Official Site.

Some of Bootstrap’s great features are a fluid grid system where you can define custom breakpoints for each column and the code validation sistem. A lot of elements are available, such as navigation bars, dropdowns, progress bars, thumbnails, carousels, buttons, accordions, popups and dozens of other functionalities.
Bootstrap must be integrated into the HTML code of the web page in order to be used. In can be added very quickly by using jsDelivr, a free open source CDN. You can also download the source files and load them locally. Since many components require the use of JavaScript, a script must be placed before the closing tag </body>. All instruction details are provided on Bootstrap’ official site.
Although Bootstrap is very versatile and saves a lot of time without having to code from scratch, it may not be the best solution for beginners who would be more comfortable with a website builder or WordPress, which is a good balance between flexibility and ease of use.
Bootstrap available for free on the official site along with a very detailed documentation of every piece of code of which it consists. There are also many examples available to download and use freely, a high quality, open source icon library and a professional themes marketplace.
Sounds interesting, I wasn’t aware of it… thx