Cross-platform mobile application development using HTML5, CSS & Javascript is known as hybrid app development. It’s an ideal solution to create & deploy the same application across different mobile platforms with the same code base.
This is pretty cost saving. HTML5 code is embedded inside the Hybrid application framework using a foreign function interface that helps in accessing resources native to the device. It’s done for overcoming the browser support limitations.
The UI layer of a hybrid application is a web browser view (web view) that takes up 100% of the device’s height & width.
The client communicates with an application server to receive data as it does not interact directly with a database. The application server handles business logic and communicates with a back-end data repository. The client to application server communication can be based upon standard HTTP requests for HTML content, RESTful XML services, JSON services, or SOAP (or WebSockets if your OS supports it).