angularjs – understanding $ mark and services-Collection of common programming errors
‘$’ Prefix Naming Convention You can create your own services, and in fact we will do exactly that in step 11. As a naming convention, angular’s built-in services, Scope methods and a few other angular APIs have a ‘$’ prefix in front of the name. Don’t use a ‘$’ prefix when naming your services and models, in order to avoid any possible naming collisions.