Confused about Service vs Factory

Question

As I understand it, when inside a factory I return an object that gets injected into a controller. When inside a service I am dealing with the object using this

Answer 1

Very simply:

.service - registered function will be invoked as a constructor (aka 'newed')

.factory - registered function will be invoked as a simple function

Both get invoked once resulting in a singleton object that gets injected into other components of your app.