while others would choose a different approach

<STYLE TYPE="text/css"> BODY {background-image: url(http://URL_IMAGE_HERE ); background-repeat: repeat; background-attachment: fixed; } </STYLE>

(There's several different ways of writing the same exact code)
<STYLE TYPE="text/css"> BODY { background-image: url(http://URL_IMAGE_HERE ); background-repeat: repeat; background-attachment: fixed; } </STYLE>

the repeat values can be altered in various ways.
W3 Schools has the best listing available:
repeat→ The background image will be repeated both vertically and horizontally.
This is default

repeat-x→ The background image will be repeated only horizontally

repeat-y→ The background image will be repeated only vertically

no-repeat→ The background-image will not be repeated

plus, there are 2 additional variables:
initial → Sets this property to its default value.

inherit→ Inherits this property from its parent element.

also, the background-attachment property can be either Fixed or Scroll.

here are examples of a FIXED background:
voy/240004 | voy/240008 | voy/230250 | voy/238891 | voy/230080

(notice how the background remains stationary. It doesn't move).
even when you scroll down the page, the background stays-in-place.

here are examples of scroll backgrounds
voy/230050 | voy/230150 | Title Of Link | Title Of Link | Title Of Link

Notice how the background moves along, when you scroll down the page.
back during the Internet's earlier days, most websites had scrolling backgrounds.