General :: Function Of Various Location Services In Jelly Bean 4.1.2

I have a HTC One running JB 4.1.2. I am confused by the location settings available in various places in jelly bean. In my previous phone running gingerbread, all the location related settings were under 1 tab. In JB, its under various tabs and apps. I am wondering what purpose some of these settings cater to. I am listing all the location related settings available in JB 4.1 below:

1. settings > Accounts & Sync > Google > Location settings > Let Google apps access your location.I believe this setting has to be enabled for google services such as maps, google now, google+, etc. to function.

2. settings > Location > Google's location service the description is given as 'allows anonymous location data to be sent to google. Also allows permitted apps to use data from sources such as wifi and mobile networks to determine your approximate location.'

settings > Location >Location & Google search.Description: 'Location used to improve google search results and other google services'

3. Google maps > settings > location settings > Under background location reporting > Location reporting (has 3 options: automatically detect my location, update location manually, do not update location)

Google maps > settings > location settings > Under background location reporting > Report from this device.If you use the above location reporting option and use same username for multiple devices, on whichever device you select this option will only report location.

There are also other options under this setting like enable location sharing, enable location history, etc.From my research, i found out if you wish to use maps and like google search results tailored to your location, then 'Let Google apps access your location' and 'Location & Google search' setting need to be enabled. Also for information, i have disabled 'Location reporting' setting listed in No .3 by selecting 'do not update location' and also disabled all other location settings listed in No. 3. But it has not affected google maps, google search, weather, google news.

I wish to know what exactly 'Google's location service' setting listed in 2 and 'Location reporting' setting in 3 does. Which apps do they exist for? I am asking this because some of these location settings i have listed above appear to have similar functionality going by their description (though that would not be the case) and i wish to know the difference. I also wish to safely disable some of these settings to conserve battery but without affecting functionality of apps like maps, search, news, weather.