Locational astrology is the umbrella term for every technique that connects a birth chart to a place on Earth. Astrocartography is the best known of them, but it is not the only one, and the German-speaking tradition in particular uses a parallel vocabulary — Weltlinien, Astrogeographie, Ortsastrologie — that maps onto the same underlying idea with different emphasis.
They do not contradict each other. A line tells you a place is worth investigating; a relocation chart tells you what that place would actually do to your chart; local space tells you which direction to move within it.
In German practice, Weltlinien ("world lines") is the everyday word for what English calls astrocartography lines. Astrogeographie is used more broadly for the whole field of astrology-and-place, and Ortsastrologie ("location astrology") usually refers to the practical question of choosing where to live. Searching for any of the three will get you to the same technique; the differences are of tradition and emphasis rather than of mathematics.
The honest boundary matters. Locational astrology can:
It cannot account for immigration law, the job market, cost of living, language, climate or your family's wishes. It also cannot separate two towns on the same line. Use it to shortlist; use ordinary research to choose.
Vertical world lines only pass through certain longitudes, which leaves large parts of the map untouched. Paran lines are horizontal bands of latitude where two planets are angular at the same moment. Their influence is subtler than a direct line, but because they run right around the globe, everyone has usable parans near home. If no world line reaches anywhere you could realistically move to, parans are the next place to look.
Any technique that links a birth chart to geography. The three main ones are astrocartography, relocation charts and local space astrology.
Yes. Weltlinien is the common German term for the planetary lines that astrocartography plots on a world map. The calculation is identical.
They answer different questions. The map scans the whole world quickly; the relocation chart examines one place in depth. Use the map to shortlist, then the relocation chart on the finalists.
No. It narrows the world to candidate regions. Choosing between two cities on the same line requires ordinary research into visas, work, cost and language.