Access the Internet with iOS Device
An iOS device can access websites and servers on the Internet through Wi-Fi or optional 3G or 4G services. This Internet access gives you the capability to create apps that can provide real-time information. An app can tell a user, for example, that the next tour at the Tate Modern in London is at 3 p.m.
This kind of access also allows you, as the developer, to go beyond the limited memory and processing power of the device and access large amounts of data stored on servers, or even offload the processing.
You don’t need all the information for every city in the world stored on the device, nor do you have to strain the device processor to compute the best way to get someplace on the Tube. You can send the request to a server for all that information, especially information that changes often.
This technique is called client-server computing — a well-established software architecture where the client provides a way to make requests to a server on a network that’s just waiting for the opportunity to do something. A web browser is an example of a client accessing information from other websites that act as servers.