Here we are going to know about the 'Web Services' in iOS, so as we know more and more mobile applications are dependent on the cloud in order to function properly (e.g. Twitter, Facebook, news apps etc.), integrating web services into mobile applications is an increasingly common scenario.

The Xamarin mobile frameworks have a wide array of support for web service integration including built-in and third-party APIs for integrating with RESTful, SOAP and WCF services. 

In this article, we examine how to utilize the Xamarin mobile framework including built-in and third-party APIs, as well as the associated tools to integrate various web service technologies, including:

1. REST Services - REST (or RESTful) Services are an increasingly common paradigm for creating web services because of their simplicity and inherent platform agnostic approach. Many of the major service providers use REST, such as Twitter, Flickr, Facebook, etc. REST allows for stateless, cacheable, and simple to consume client-server architecture over HTTP. This article examines a number of third-party options for consuming REST services, including; RestSharp, ServiceStack, Json.NET, etc.
2. WCF Services - WCF is a Microsoft specific web service technology that aims at abstracting implementation from transport and data technology. Xamarin mobile applications support the consumption of WCF services that are exposed via the BasicHttpBinding protocol, by using the Microsoft Silverlight SLSvcUtil.exe utility for client proxy generation. 
3. SOAP Services - SOAP is a standards-based web services technology that allows providers to abstract data and transport implementations over the web. Xamarin mobile applications support standard SOAP 1.1 implementations over HTTP. Additionally, we support the Microsoft specific SOAP implementation, ASP.NET Web Services (ASMX), which allows for implementation of standard SOAP, XML and JSON responses.