Responsive Design or more precisely Responsive Web Design (RWD) is a digital interface design technique that ensures that the display of any page on a site automatically adapts to the size of the website. ‘terminal screen that reads it.
It is different from Adaptive Design although the two concepts aim to improve the mobile ergonomics of the website.

Self-adaptive web design is the expression that best explains this technology for displaying websites on a mobile device.
The objective is of course to facilitate the reading and navigation of the Net surfer regardless of the type of terminal he uses.
With a smartphone, a tablet, a netbook, a connected TV or simply a computer, the page will appear complete and ergonomic to him without any manipulation to be done at the level of the zoom in / out and the horizontal scroll bar. The site code adapts its layout according to the screen that presents its pages. There is an automatic resizing of the textual and graphic content blocks as well as a reorganization of their arrangement.
This solution which can be summarized by the expression “Mobile first” is a response to the current trend of Internet users to use more and more mobile devices and was made possible thanks to CSS3 Media Queries.
Behind this self-adaptation are an identical HTML code for the different types of terminals, graphics with adaptive resolutions, a fluid grid system and of course the CSS3 Media Queries which manage the style sheets.
A rule allows web designers to easily manage the creation of this design.
It is a question of starting from a display in 320 px then to go up towards resolutions larger and larger.

The advantages of the RWB are important, at least as long as the web designer does it well in its design, that is to say if it takes care of the content of its pages, anticipates the behavior of the users, takes into account the functionalities of the different touchscreen terminals and knows how to exploit the tendency of resolutions to grow. The simple Drupal V8 as well as the powerful version 3.8 of the WordPress CMS are at its service to do this.
To create a site that adapts to all displays, he will only have to develop a single HTML code.
On the user side, the positivity of the experience in terms of ergonomics no longer needs to be presented.
However, perfection does not exist since this ability to be adaptive on mobile screens is accompanied by a degradation of the page display speed.
The reason is that the RWB has to load the entire CSS file.
Although this degradation is minimal, it can be sufficiently penalizing for certain mobile applications to justify the choice of a solution other than Responsive Design.
There is still a possibility for the creator of the site to only allow certain content elements to appear on resolutions higher than those of smartphones to circumvent this kind of problem.
It should also be noted that this page loading time has only a very low impact on the positioning in terms of SEO but is of great importance for the mobile user.

This is the rate of visitors leaving your site without having browsed other pages. While some high bounce rates can be an indicator of quality (for example a directory for which members' pages are well indexed, and found directly via Google), in general we will ensure that the bounce rate is as low as possible.
Typically having a high bounce rate isn't a good thing for a site. The bounce rate is simply the percentage of visitors coming to a site and leaving without opening a page or clicking on a link. And to calculate the latter, it suffices quite simply to make the ratio between this type of visitors and the total number of visitors. So, we might as well be clear: if it is true that depending on the type of site the bounce rate may vary, we still agree that when it exceeds 50% it is a bad sign… On the contrary, if this is less than or equal to 30%, this is excellent news for the site. But in the case of a rather high bounce rate, we also recommend analyzing the visit time on Google Analytics,because it is possible that some visitors see only one page, but stay there for a while.

As stated above, the bounce rate should be analyzed differently depending on the site. Thus, with regard to e-commerce or information / news sites whose strategy is obviously to encourage each visitor to consult several pages, they can in no case afford to have a rate of bounce greater than 50% without worrying about it. On the other hand, other sites that claim to be dictionaries or directories, which visitors generally only consult for one specific reason, may have a higher or lower bounce rate. Finally, it is also a matter of adding that when we take the time to analyze our own bounce rate, some visitors are considered outgoing even when they click on a link on the site. This is particularly the case in the context of outgoing links.