Today everyone has their smartphones with them, constantly communicating and looking for information.Mobile is changing the world. In many countries, the number of smartphones has increased significantly ratio to the number of personal computers. To have a mobile friendly website has become an important part of having an online presence.Since 2018, Google ranks the mobile version higher than desktop versions. In many industries, mobile traffic today accounts for 50% - 80% of all internet traffic. In order to rank as high as possible is important to have as short charging time as possible. A web site should look just as good on different devices such as PC, mobile phone or tablet Responsive Web Design makes your web page look good on all devices (desktops, tablets and phones) and is about using HTML and CSS to resize, hide, shrink, enlarge or move the content to make it look good on any screen.Easy to understand course that gives you step-by-step information on how to customize your website.