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This article helps you to start in CSS3, explaining the basics of how to display elements in an HTML document. The key to using Grid is to know which element is the parent (as a container) and which elements are the children. Using Flexbox it is possible to put some elements in different positions and displayings. It was important for me because many times I had problems with the vertical and horizontal positions of divs, spans, and images. Media Queries the web pages can reconfigure their web pages with conditional screen sizes.