All location information added to your event(s), is used to determine the location of your event on the map. However, sometimes there are multiple options. For example a street name exists in multiple cities, or a neighborhood is also a street name.
In those cases the top ranked location will be used, which might be the wrong location for your event. You can then change the location of the event, by adding more details in the “location” field of the event.
Of course, the more detailed the information, the more reliable the result will be.