The Location field can be used to either capture the users current location, or a user defined location. The location will be capture the latitude and longitude of the location in the field. In the field settings you can toggle the "Allow User Defined" setting, which will allow the user to mark a custom location in the map, otherwise the field will only capture the users current location.
You can use this field if you want to capture the location of your current job site. Or you can use this field to mark the location of nearby job sites.
When using this field the app will capture you current location by default, however if the "Allow User Defined" is enabled you then do a long press on the map to set a custom location.