How The Web Works
We’ll talk about websites. I.e., when you type a URL into your browser (e.g., “webcity.net.au”) and get a website in return.
The internet, however, is more than that. You use it for a lot more than that every day!
Requests and responses always have the same basic concept. However, not every response is a website. And not every request necessitates the creation of a website.
Metadata attached to requests and responses determines which data is desired and returned. Of course, both parties involved (client and server) must be able to support the requests and data sent.
For example, you can’t get a PDF from “webcity.net.au” You could make such a request, but you wouldn’t get a PDF in return because we don’t support this type of data request for this URL.
However, there are a number of servers that specialize in providing URLs that return specific data. APIs are another term for such services (“Application Programming Interface”).
To get or store data, mobile apps send “invisible” HTTP requests to such APIs (to specific URLs that are known to them). For example, Twitter is retrieving the tweet feed.
Such “invisible” requests are sent even on webpages. No new page will be loaded if you sign up for our newsletter (which you should do!). Because data is passed back and forth behind the scenes. Even though the client in this case is the browser, the request that is sent does not expect a website in return. The server URL that receives it, on the other hand, does not offer a website; instead, it knows how to handle your email address.