C:\Program Files (x86)\Ampps\!HTML_Prac\Misc\Castro\Code Examples refers to the web page supposedly showing codes.
ECLoc8610, Page 268 refers to complete code for various facets of the page.
First examination leaves me with confusion. It is not easey to understand as presented.
I shall refer to W3Schools.com to learn about block.
Compared to display: inline, the major difference is that display: inline-block allows to set a width and height on the element.
Also, with display: inline-block, the top and bottom margins/paddings are respected, but with display: inline they are not.
Compared to display: block, the major difference is that display: inline-block does not add a line-break after the element, so the element can sit next to other elements.
The following example shows the different behavior of display: inline, display: inline-block and display: block:
I stopped here: ECLoc8539, P267