Understanding of display: inline; and float: left; _ CSS/HTML

First of all, we need to be clear about display: inline; and float: left. Display: inline; (inline) text display in CSS authoritative guide: any visible element that is not a block-level element is an inline element. Its performance is in the form of "Row layout", where "Row layout" means that its performance is always displayed in rows. For example, when we set an inline element border-bottom: 1px solid #000, it is represented by repeating each line, and there will be a black fine line under each line. If it is a block-level element, the displayed black line will only appear below the block.

Of course, this does not seem like the difference between display: inline; and float: left; but when we understand the features of float: left;, we know exactly what is going on. Float: left; (left floating) It makes the specified element out of the normal document flow and produces a special layout feature. In addition, FLOAT must be applied to block-level elements, that is, FLOAT is not applied to inline labels. Or in other words, when FLOAT is applied, this element will be specified as a block-level element.

As we can see, the inline (display: inline;) element cannot be set in width or height, because inline is a row layout and its feature is to layout in a row, therefore, the width and height cannot be set.