How do android or iphone clients work?

I'm trying to understand this concept but I don't get it yet. I'm new to mobile connections.

How do mobile apps and/or clients connect to the internet, if they do? if not, then, how do they serve real time d开发者_开发技巧ata from remote servers (like twitter, fb) etc..?

I've heard that mobile apps don't require internet connection but I'm confused because I don't know how they get the data from the servers of twitter or fb or any application.

For example m.facebook.com is a site so it'll only work with some type of connection on a mobile, but with the app.. what happends (how do all of a sudden you don't need internet connection to serve the data from their servers)????

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Think of a Web browser. It's an app that issues HTTP requests over the 'Net and interprets the response by rendering HTML and images, running scripts, etc. Now, there's nothing magical about the browser; it's just a program with HTTP capability.

Any other app can do the same. Except it does not have to interpret the response like the browser does. An app can just as easily issue HTTP requests and do stuff to responses. That's how Facebook, Twitter etc. client work. They normally work, however, not with user-facing parts of the target site, but with software-facing bits (called "The API").

Not all mobile apps require or use the Internet. Most games, for example, don't. But the apps that interact with websites, like Facebook, do.