Relative location is basically the area where a certain person or thing resides. As it is moved around, there is a change. It could be due to a number of reasons. An example of a change in relative location is people moving inland due to a contagious disease.
They do this to prevent spread and protect themselves as well as others. In some cases, such as this one the process is important in order to isolate and contain the damaging agent. This works for the greater good. Other things that can be an example include objects such as containers or entire buildings that are shifted, resulting in a change in relative location.