Angular .service() or .factory(), which one is better

.service() is just a Constructor, it’s called with new, whereas .factory() is just a function that returns a value.

 

Using .factory() gives us much more power and flexibility, whereas a .service() is essentially the “end result” of a .factory() call. The .service() gives us the returned value by calling new on the function, which can be limiting, whereas a .factory() is one-step before this compile process as we get to choose which pattern to implement and return.

 

refer this for more info

https://toddmotto.com/factory-versus-service