A web-based application often provides an HTTP-based API using a variety of protocols (https://en.wikipedia.org/wiki/List_of_web_service_protocols) that allow access to the application functionality via the internet. HTTP stands for Hypertext Transfer Protocol, which is an application protocol for distributed information systems that serves as the foundation of data communication for the World Wide Web (WWW).
The two most popular web service protocols are:
- XML-based SOAP (Simple Object Access Protocol) protocol
- JSON-based REST or RESTful (REpresentational State Transfer) style over HTTP protocol
Both describe how functionality (services) can be accessed and incorporated into the application. We do not describe web services in this book.