Population registers can be difficult to understand, because one page can have information about people at different times. This can be especially confusing for people who are used to dealing with census records. Here’s an analogy that might help you:
Census records are like snapshots, population registers are like movies.
Population registers record what is going on with a family over a period of time, usually about ten years. By reading the lines from top to bottom, you will see who enters and exits the household. The people at the top of the page were there when the register was started. People were added when they were born or moved in. People were struck through when they died or move out.
People who leave and come back again will appear multiple times. There can be two people on the same page who never actually lived in the same house at the same time. They may not even have known each other if a different family moved in.
For an example of how to use this temporal aspect of population registers in your research, see the article Case study – Subtle clues in population registers.