...It gives you an elegant interface on top of Apple’s URL loading system provided by the Foundation framework. It wraps the URLSession API among others in an easy-to-use interface and provides additional functionality required of modern application development using HTTP networking.
Alamofire offers plenty of features, including Chainable Request / Response Methods, URL / JSON Parameter Encoding, Authentication with URLCredential, and HTTP Response Validation. Additional component libraries by the Alamofire Software Foundation also bring additional functionality to the Alamofire ecosystem.