Web Services is a generic umbrella that describes how disparate systems can integrate with each other over the web.
Most major sites offer some form of web services:
Why use Web Services?
- Someone else has data you need
- Easier than scraping pages also more reliable
- Automate processes
- Provide additional information to your clients
- Representational State Transfer
- Requests look like filled out forms, can use either GET or POST
- Response is an XML document
- Request and Response is defined by the service provider
- Very simple and popular