Those who just starting to become a Front-End Web developer, you should check out this website on CSS article by Johna Paolino:

For years, designers have been using grids to bring order to pages. Grids as a design tool are associated with the Swiss who formalized it as a way of thinking about layout in the 1940s, according to Beth Tondreau in the book “Layout Essentials”. As people started designing for the Internet, grid systems were carried from the printed page to the digital one. https://open.nytimes.com/css-grid-for-designers-f74a883b98f5