A design philosophy that, as its name suggests, puts mobile devices first. It is about designing thinking about the characteristics of mobile phones first when developing a website, content or software. To do this, it is essential to take into account the more limited dimensions of the screens of these devices, as well as the tactile method as the main system of interaction.
Currently, the practice of 'mobile first' is the epicentre of most design-related initiatives. Its link with responsive design can lead to confusion, but while this part of the idea of developing a desktop version that can later be adapted to mobile devices, the 'mobile first' always puts these devices first.