In brief
pre-wrap stores the spaces and new lines, and also allows for carryover.
Useful to know
white-space determines how the browser handles empty characters and porting. In the usual normal sequences of intervals contract . pre-wrap retains the intervals and explicit new rows, but allows the long rows to be carried according to the available width. [1]
This is appropriate for a short note entered as plain text: the author may have divided an address or instructions into lines. With pre-wrap, these divisions remain visible without each row receiving a separate HTML element.
Storage of whitespace does not imply authorization to execute HTML. The user text should be displayed with the correct escaping for the ; CSS application only solves the visual representation. If there is a very long address without spaces, check also a separate rule for carrying continuous strings, instead of expecting white-space to solve each case.
Sources
For further detail and to check the information: