AngularJS: Difference between service, factory and provider

In AngularJS, service, factory and provider are all ways to create reusable components that can be injected into other parts of your application. However, there are differences in how they are created and used.

Service

A service is a constructor function that is instantiated with the 'new' keyword. It is a singleton object and is instantiated only once per application.

Factory

A factory is a function that returns an object. It can be used to create multiple instances of the object. Factories are often used to create resources that need to be created multiple times.

Provider

A provider is the most configurable of the three. It is used to create services that can be configured before the application starts. Providers can be used to create services that have configuration options.

In summary, service is a singleton constructor function, factory is a function that returns an object, and provider is the most configurable of the three. Each has its own use case depending on the requirements of your application.