Today's most prominent internet browsers support a set of syntax for CSS files that allow them to dictate grid-based layouts for webpage content. This is called CSS Grid Layout, and the reason a web developer would use it over straightforward HTML-based tables is that CSS Grid better allows a segmented webpage to retain its structure across many different screen size dimensions. Because this can alleviate the need for web developers to contend with painstaking positioning, this is an important quality for a web page that is meant to be displayed across many different types of devices and display screens.
CSS Grid allows a webpage to have rows that stay consistent in their dimensions and display the page's primary contents while simultaneously allowing dynamically scaling "separating rows" that make up the blank space in between the content-filled rows. In a particularly complicated example of how this can be done, an article by freelance web developer Dan Webb on itnext.io explains how the syntax that is exclusively associated with the CSS Grid Layout module can be made to host precise percentage and pixel values that define every row and column.
To define the grid syntax horizontally, Webb assigns extremely specific percentages to the width values of all of his page's columns so that they can dynamically widen and contract proportionally to the size of the display window itself. Each of his grid layout's rows, meanwhile, have their respective heights defined to be set either to straightforward pixel values or to dynamically scaling "auto" values. The website also shows that the CSS syntax can define individual grid elements called "nth-child elements" that dictate which stretches of a grid are to be counted as shared cells spanning multiple table cells worth of grid space.
It should be noted, however, that the example posted on Webb's article needlessly works out incredibly specific percentage values to define the dynamic widths of each of his columns. CSS Grid provides special and dynamic measurement units that can be used in their place to simplify the design process; columns' widths can be defined as "6fr," "4fr," and the like. For more information click here https://itnext.io/how-to-build-complicated-grids-using-css-grid-609b1197cf75.