Responsive website in practice
A responsive website adapts to the screen it is opened on: on a computer it might show three columns side by side, on a smartphone it stacks them one under the other, enlarges the buttons and resizes the images. It is a single website, with the same content and the same address, not a separate «mobile» version to update on its own.
Think about when you look for a restaurant, opening hours or a number to call: you almost always do it on your phone, often while out and about. If the site is awkward, you go back and pick another one. Google also evaluates websites mainly in their smartphone version, so a site that is hard to use on mobile suffers in SEO too.
An example: a beauty salon publishes its price list in a table eight columns wide. On a computer it is clear; on a phone it forces you to scroll sideways and zoom in. In the responsive version each treatment becomes a card with name, duration and price, and the «Book» button stays within thumb's reach. Sometimes it pays to go beyond simple adaptation: for Claudia Loperto Architetto we created a different opening for desktop and phone.
When you check a website, do not just narrow the browser window on your computer: open it on your phone, on mobile data. Check that the text is readable without zooming, that buttons are not too close together, that the phone number and address can be tapped to call or open the map, and that forms are comfortable to fill in. The core Web Vitals should also be checked on smartphones first.