Flex and Grid Systems. Fluid Image Use. Media Queries. = mobile, desktop, and tablet friendly user experience.
RWD means a specific approach to modern, i.e. adaptive web design. What kind of Internet content we want to create when we say we use responsive web design? In every case, that content would have to be very easy to use, but also adaptable for everyone's devices (due to different screen sizes, e.g. mobile phones and tablets).
When we decide to build an RWD site, we actually use fluid grids that serve to basing and determine the proportions of certain device screens. Flexible images make the experience and content experience on every different device with equal and high quality. In addition to fluid lattices and flexible images, it is good to mention the special technologies used in the creation of responsive web design.
Here we are most often referring to CSS which is able to unify all contents for different devices. It is recommended to research different CSS systems and find the ones that are the best fit for all kinds of devices for which you want to create a responsive web design. An example of customizing items on the site with the help of the CSS system - margins, font size...
Customizing the appearance of the website appeared out of the very need of modern society, and these ideas for its use and application arose spontaneously, with the change of the world and technology.
The main motive behind the existence of responsive web design is that more and more people around the world are using it various devices for searching content online, such as smartphones.
Imagine what would happen if sites were not optimized for your computer and phone in the same way?
Maybe you want to check out something you saw outside your home, but if that website wasn't edited by principles of RWD, you would be denied the information you wanted to review over the phone, and you had to wait until you got back home to do it again.