* The CSS Box Model is a box that wraps around every HTML element. CSS determines the size, position, and properties (color, background, border size, etc.) of the boxes. Each box consist of 4 areas, defined by their edges: the content, padding, border, and margin edge. https://developer.mozilla.org/en-US/docs/Web/CSS/CSS_Box_Model/Introduction_to_the_CSS_box_model
* The difference between the padding and the margin is the padding creates space within the element, whereas the margin creates extra space around the element.
* There is a default or automatic HTML height and width setting, bu the HTML's height and width may also be specified in length values like px, cm, etc., or in percent (%) of the containing block. ://www.w3schools.com/Css/css_dimension.asp
* The CSS padding properties define the space between the element border and the element content. In sequence the numbers rotate from top, to right, to bottom, and to the left.To understand the CSS padding property example, padding:25px 50 px,There are 4 available ways of setting the property values. One number will indicate all 4 sides have an equal value.With two numbers, as the example above, the first number indicate the top and bottom padding spacing, and the second number dictates the right and left padding spacing. With 3 numbers the first number is the top padding, the second number are the left and right padding, and the third number is the bottom padding. When there are 4 numbers the sequence is listed above. ://www.templatemonster.com/help/css-understanding-border-margin-and-padding-properties.html
* The difference between a border and an outline is that a border may be adjusted by height and width, whereas outlines do not take up space, and are placed on top of the element box. Outlines are the same on all sides and can only be a single color and do not change the position or size of an element. ://www.tutorialrepublic.com/css-tutorial/css-outline.php