Yet in many other countries, they do not maintain legal deeds. They still resort back to land boundaries defined by metes and bounds. Metes and bounds is land marking by trees, rocks, or other natural markers. The problem with this is that the natural world is dynamic and these markers move with time. The U.S. used to use this practice, but most of the landmarks have disappeared with time.
Most attribute data is obtained through census tracking.
The problem with census data is that the methods by which it is obtained is sometimes under scrutiny. Today much of the census data is based on samples. By using statistical strategies, census data is calculated by averaging the number of people seen in an area and taking that average and multiplying it by the size of the area. This will give you a fairly accurate reading of the number of people living in the area, but it does not take into account every person living there. Many people simply don't want to be counted.