I suggest that you check the ArchiCad manual, or use the Help Key (F1)to get the manual online. I seem to remember the manual explaining it quite well.
Cornelis (Kees) Wegman
cornelis wegman architects
AC 5 - 26 Dell XPS 8940 Win 10 16GB 1TB SSD 2TB HD RTX 3070 GPU
Laptop: AC 24 - 26 Win 10 16GB 1TB SSD RTX 3070 GPU