What is a border on a map?

generally a prominent line of some sort

maps often show borders but not always

more important borders are usually shown as bolder or more continuous lines than less important borders

the lines may be comprised of dashes or of dots or of dashes & dots etc

many European maps show international borders as lines of plus symbols & subdivisional borders as lines of alternating plus & minus symbols

Russian maps show international borders as lines of a symbol that looks like the capital letter i

etc