In the 21. century it is inevitable, that our website is visible not just on the computer but on other devices (mobile phone, tablet), too, without loosing visual experience. As 20-30 % of the users are surfing on their mobile phones and tablets on a daily basis, these users have to be considered as a potential target group, therefore it is essential to optimize websites to other devices. The so called responsive appearance is a mobile-friendly design, which ensures, that the website looks good on other devices, too: in this case the site switches automatically to the presentation of the device used by the visitor. Responsive presentation is definitely recommended.