What is the difference between Location sharing and Find My iPhone?

If you are tracking someone in your family, for example, you'd set it up as shown via Family Sharing and you can track their location en route, regardless of where that person is (overseas, it matters not). You click on Find My Friends app, a map opens up and you see that person's progress along the highways and byways....

"The family organizer sets up location sharing in Family Sharing settings. After location sharing is turned on, the organizer's location is automatically shared with everyone in the family group. Then each family member can choose whether or not to share their location. When you agree to share, your family members will be able to see your location in Find My Friends and Messages. And you can see where they're located too.

Plus, with location sharing enabled, if one of your devices is lost or stolen, you can ask a family member to use Find My iPhone to help you locate it and get it back."

From

Set up Find My iPhone on all of your devices - Apple Support

Find My iPhone helps you locate and protect your Apple device if it’s ever lost or stolen. Just sign in to iCloud.com or the Find My iPhone app to see your missing device on a map, play a sound to help you find it, use Lost Mode to lock and track it, or remotely erase all of your personal information.

From

https://support.apple.com/en-us/HT201087

What if find my i phone isn't on and someone hard reset it using iTunes restore. will this affect me finding my phone ?