Consuming web services allows you to extend your applications and business processes with capabilities that are provided by various third parties. For example, if your application need to convert an address to geographic coordinates (such as latitude & longitude), you would most likely use the Google Maps Geocoding API to do that. Being able to consume web services often add enormous value to your applications as you wouldn't otherwise have the resources to provide these extra functionalities to your customers.
Next: Software Pre-requisites
