What does mobile first mean?
Mobile first is a methodology for building web pages where it is first designed for mobile devices and then adapted to computers. Appearance on small screens is given more importance than on big screens and this way ensures that everything works perfectly on mobile phones.
Why should I make a mobile first web?
As we have seen in the graphs above, the majority of Internet searches are done through mobile phones. Most likely, your website will receive more visits from mobiles than from devices with larger screens, so it is more important to focus on designing for small screens.
In addition, Google rewards responsive websites by giving them a better position in the organic search ranking and a higher score in Adwords campaigns, so your website will receive more visits.