This translation is machine-generated and pending review.
The concept of responsive design is not new: it began in 2004 and became popular in 2012 as an evolution in the logic of web design. It has been getting a lot of attention lately with the growth of the mobile device market. With this technique the website adapts to the size of the user’s screen, adjusting its design and content with the goal of delivering the best experience to the user. 
Imagine the following situation…
A simple example: if you visit a travel agency’s website through your desktop, you are going to look for references, photos, additional services they offer, and so on. But if you look up the agency on your phone, stuck in traffic in your car, all you need is to find the contact number and the address as quickly as possible, right? That is the premise of mobile-first, an experience optimized for each device. What needs to be conveyed on a 4-inch screen in a simple and easy way? The website always takes on different functions depending on the context of use. 
I’m still not convinced!
I gathered a few reasons to convince you that Responsive Design is the best way to go.
- Far beyond beauty, responsive websites guarantee an optimized experience for all devices, including those that haven’t been released yet.
- They are considered the best Mobile-Friendly solution and, as determined by Google, this becomes a heavily weighted criterion for the site’s ranking in search engines.
- Having one site for desktop and another for mobile requires double the SEO and marketing planning; having a single site makes it easier to manage.
Fun facts
• There are more than 230 screen sizes across different types of devices • 67% of users say they are more inclined to buy on responsive sites • 30% of consumers access their emails exclusively from mobile devices
I want to start building a responsive website, where do I begin?
I gathered 3 frameworks I have already worked with; they are quite famous and, in my opinion, the best ones to start with. A quick search and you will find plenty of tutorials. https://metroui.org.ua/ http://getbootstrap.com/ http://foundation.zurb.com/