The design of a website is called a layout. The layout includes positioning and margins, borders, padding, and content. A CSS template website design can easily include all of these things. In CSS, the layout is often called the box model. It is referred to as a box model because elements of the website are placed in boxes.
An easy way to understand why CSS layout is called a box model is to picture a blank computer screen. In the center of the computer screen is a small box – box number 1. Around box number 1 is a second, larger box – box number 2, surrounded by box number 3, which is surrounded by box number 4.
The content, text, pictures, etc. go inside box number 1. Box number 2 contains the padding, the amount of empty space around the content. Box number 3 is the border, which can be any size or color. Box number 4 contains the margin, which is the amount of empty space around the entire website, similar to the margins on a piece of paper.